Author Existence Failure: The death of Hillel Slovak. Thankfully averted (very nearly played straight) with Kiedis and Frusciante.
Black Sheep Hit: "Under the Bridge" was such a different type of song than they usually recorded that Kiedis initially didn't want to put it on the album. Of course, he did and it was a runaway success and possibly their best-known song.
Creator Backlash: Anthony doesn't like "The Greeting Song" very much - it only exists because Rick Rubin told him to write a song about girls and cars.
Anthony has also complained about "Knock Me Down" and refuses to do it live, complains about the One Hot Minute period despite fan desire to hear the tracks, and basically regrets his personality in the 80s even though he was really cool.
Creator Breakdown: Many times when either John or Anthony have slipped into drugs and rehab, but both Anthony and John have now been sober for more than 10 years each, with Anthony having the significant sobriety date of Christmas Eve, 2000.
Doing It for the Art: John Frusciante's attitude for a long time was to stay out of the spotlight and just play music, and avoid anything that could be construed as "selling out"; he left the band at one point over it.
The reason he ended up leaving the band was that his heroin addiction was affecting his will to perform live. The whole "selling out" thing was partly true, but was ultimately a more palatable story to tell the media. Another part that the media rarely hears is that Anthony was bullying him, which made him feel too much like being in the band was a job. This is part of the reason why John was given so much creative control in the Californication period onwards - Anthony felt guilty about the way he'd acted.
Dye Hard: Anthony dyed his hair blonde during the Californication era. Went back to the usual color by the time By the Way came out.
Not quite. During the By The Way period his hair was actually dyed black. Usually, it's a medium to light brown.
Flea has constantly been known for dying his hair various colors, most frequently pink and blue. He is doing it more often because his natural hair color has faded over the years.
Chad Smith bleached his hair in the One Hot Minute period, as can be seen in the back page of the album's booklet and some posters for the period. Before that he had long black hair. For the Californication period onwards he shaved it off and wore a hat or bandanna, and has remained that way since.
Promoted Fanboy: John Frusciante was a devoted follower of the band's early early career, before becoming their guitarist in 1988.
Now this has happened twice with Josh Klinghoffer, although he was a long time friend of the band by this point (having already recorded with John Frusciante and toured with the band). The band knew Josh since 1997, when he joined their mutual friend Bob Forrest's band "The Bicycle Thief". The bands toured together in 2000, and Josh became great friends with John Frusciante, recording several albums together, both as part of John's solo work and as Ataxia. Klinghoffer toured with RHCP as an additional guitarist on their Stadium Arcadium tour in 2006-2007. The band took a year's hiatus, after which John Frusciante left, and Josh stepped in to fill his place in 2008. It was only officially announced in 2010 that Josh was their guitarist. It's believed that his appearance on tour was a way of testing him out to fill Frusciante's role, but the rest of the band apparently did not know Frusciante was going to leave. Josh has shown his love of the band, particularly their early work, by often teasing songs they would never perform live in full. He does this considerably more often than Frusciante did.
The Other Darrin: Four drummers and eight guitarists have been official members of the band. While every drummer recorded with the band at least once (Cliff Martinez played on the first two albums, Jack Irons on their 1983 demo and on their third album, and D.H. Peligro recorded a song called "Blues For Meister". Additionally, he received writing credits on several Blood Sugar Sex Magick songs), some of the guitarists weren't so lucky. Jack Irons has averted this by becoming famous with Pearl Jam.
DeWayne McKnight recorded with the band only once on the aforementioned Blues For Meister, and played three shows with them while he was an official member of the band before being fired.
Arik Marshall never recorded an album or wrote a song with the band during his tenure with them, although he did play several high profile shows with them, namely Hollywood Rock and Lollapalooza. Also, he appeared with the band on The Simpsons episode "Krusty Gets Kancelled".
Jesse Tobias was the guitarist recruited to replace Arik Marshall. One month later, the band realized they didn't have much chemistry with him, so he was fired when they discovered Dave Navarro was available.
Jack Sherman and Dave Navarro are seen as this by most fans, although they both got to record on an album. They were snubbed when the band was inducted into the Rock and Roll Hall of Fame due to the Hall Of Fame only allowing a limited number of members in. And, although he was one of the inductees, Josh is seen as this by a lot of fans.
Then there are several other people considered for the band (even considered official members by some, despite not signing any contracts) that never made it in. Phillip Fisher recorded a song (Taste the Pain) with the band after Peligro was fired and before Chad joined, but he was never an official member.
After Slovak quit, a friend of the band and then-Thelonious Monster guitarist Dix Denny was asked to replace Slovak, but they opted instead to audition guitarists after a few jam sessions with him revealed that they lacked chemistry.
After Frusciante left for the first time, Zander Schloss of Circle Jerks was called in to be his replacement, but again, he lacked chemistry with the band, and so an entire leg of the tour was cancelled (however, some still consider his four days with the band an official tenure - For a long time, he was listed as a full member at TheOtherWiki.
Then there's Chuck Biscuits, who was brought on to play with the band for some dates during the Freaky Styley Tour, but shortly afterward Jack Irons quit playing for "What is This?", so Biscuits was fired in favor of the original drummer.
Finally, there's Bob Forrest and Keith Morris, both of whom filled in for Anthony during some shows in the eighties. Keith filled in at least once, when Anthony was off scoring drugs, but Bob was closer to being an actual member than him, since one of the times he filled in for Anthony was during the month he was fired.
The Pete Best: Anyone other than Anthony, Flea, Chad, John, Josh, Hillel, Jack and Dave is hard for a casual fan to remember (and at times, even hardcore ones!).
Reclusive Artist: John Frusciante hates being famous and it's a miracle he ever came back after he quit the first time. During his time away from the band, he continued making music but largely avoided playing shows.
And again, he has not played a live show in years, does not give magazine interviews and rarely appears in public.
For starters, what if Hillel Slovak and Jack Irons had stayed with the band instead of going to "What is This?"
How different would the first two albums have been if the original line up had played on them both? What if the band had kept one of their many other guitarists/drummers instead of firing them? It's important to note that Jack Sherman actually brought some mature songwriting to the band that he rarely gets credit for. Hillel and Jack considered the band something of a joke at the time due to the fact most of their songs were funk rap with comedic lyrics. Flea, Jack and the producer Andy Gill came up with the most emotional song of RHCP's early career, the instrumental track "Grand Pappy Du Plenty" at that point.
But probably the biggest examples come after the end of John Frusciante's first tenure with the band. The band went through three guitarists before getting their initial pick for John's replacement, Dave Navarro. Two of them, Zander Schloss and Jesse Tobias, never even performed live with the group, but the one between them, Arik Marshall, played many high profile shows with the band, so we at least have some kind of indicator of how an album made with him would sound.
However, probably one of the biggest "Could Have Beens" is the fact that before they recruited Jesse Tobias, Buckethead auditioned without even knowing any of the band's songs. Despite that, the band still applauded "raucously" after he finished playing, but he was passed over because the band was looking for someone who could "kick a groove."
Anthony actually cited that after the band recruited Jesse Tobias, they realized his heart was not in it. Part of that was because of Jesse's completely different sound, but mainly because Jesse himself did not feel that he should be in the band.
Vindicated by History: The closing track on the band's first album, the dark and melancholic "Grand Pappy Du Plenty", is commonly regarded as an important milestone in their career. At the time, it was so drastically different from anything else that it wasn't really noticed. Since then it became clear the band were inspired for it for the commonly regarded fan favorite "Venice Queen", its popularity has gone up considerably.
Many fans viewed By The Way as a complete sellout in its day. Since the band returned to their funkier sound for Stadium Arcadium, a lot of fans went back to By The Way and found it was far better than they expected.