The ending theme may not immediately be ear-wormy, but if you give it time, it will grow roots.
Whether you like it or not, it can easily get stuck in your head.
"A-ru-ko~! A-ru-ko~! Watashi wa genki~!" ("Let's go walk, let's go walk! I'm really feeling good!")
Ensemble Darkhorse: With all of the fanart and merchandise, you'd think that Catbus were a main character rather than one who only appears in a couple of key scenes. He even got his own short film made exclusively for the Gibli Museum in Japan.
The visual◊ of Satsuki with Mei on her back waiting at the bus stop with Totoro is one of the most popular and oft-parodied scenes in all of animated film.
Miyazaki's Syndrome, which first appeared in this movie—during the scene Mei plays with the sleeping Totoro rather than displaying the slightest bit of fear or even hesitation. That Dude in the Suede describes it as "all children losing every sense of self-preservation and only experiencing childlike wonder and amazement."
Subbing vs. Dubbing: There's no real unanimous agreement over which is the best way to see the film: with the Japanese version, the Troma/Fox/Streamline dub, or the Disney English dub? As with most hotly debated dubs, you'll have to decide for yourself.
Two preadolescence girls bathing with their father? He must be a pedophile! Actually, such a thing is considered perfectly wholesome family time in Japan and many other countries. Including some parts of the US, actually (although usually when the children are very young, i.e, not Satsuki's age).
The sequence where Mei gets lost attempting to deliver an ear of corn to her mother includes her sitting by a row of statues. In Japan, such statues represent the Bodhisattva Jizo, the Buddhist deity who is the protector of children, so the director was trying to convey to the audience that Mei is in no immediate danger while her sister and King Totoro come for her in the Cat Bus. (Ironically, within That Other Theory, this scene is offered as one of the proofs that Mei is dead, since Jizo is also the protector of dead and unborn children and infants.)
There is a scene in the middle of the movie where Mei and Satsuki are helping clean tatami mats. It's an unremarkable scene for anyone from Japan (or anyone with a knowledge of Japanese culture) but viewers from other regions were often left confused as to what the two girls were doing.