Fair for Its Day: There were no main cast members of color on the show, but, particularly in later seasons, there were several African-American guest actors, in roles that were treated with total respect. "That's My Boy?" not only presents an affluent middle-class black couple, but ends by revealing that Richie goes to school with the couple's kid (and in fact the African-American boy gets better grades than Richie) — a somewhat risky line at a time when integrated schools were still controversial.
"Funny Aneurysm" Moment: In "My Husband Is Not a Drunk," Rob becomes a Hypno Fool, with a bell making him act like a falling-down drunk. In 1974, Dick Van Dyke publicly admitted to having had a serious drinking problem for the preceding 25 years.
Getting Crap Past the Radar: In the episode "There's No Sale Like Wholesale", Rob goes to a friend of Buddy's to get a fur coat for Laura. After he gets there and picks out the style, he realizes he doesn't know the size. A janitor, who is a man with a small frame, walks by, and Rob asks him if he'd put on the coat. The guy gets a funny look on his face and says, "Are you in show business?" Rob replies yes, and the janitor says, "Look, I don't go for that!" and hurries off. Later, Rob has the coat on himself to look at it in the mirror, and the janitor walks past again and sees this. He asks Rob, "Does your mother know you do this?"
In the episode "Brother, Can You Spare $2500?", a pawn shop owner suggests to Rob that a show about a pawn shop owner would be a hit. How right he would be.
In the episode "Go Tell the Birds and the Bees," Richie asks Rob whether a fox and a rabbit could fall in love. Rob says no, but come 2016 and lo and behold...
Mondegreen: In the "Head of the Family" pilot, the Alan Brady character was originally named Alan Sturdy. This was changed for the series because it sounds like "Alan's Dirty".
Nightmare Fuel: The final shot of Rob's nightmare in "It May Look Like a Walnut", with him being cornered by the crazed-eyed Laura, Mel, and Buddy (who possibly are actually aliens/transformed), is surprisingly freaky.
Not So Crazy Anymore: in the episode The Plots Thicken, Rob is flabbergasted while talking to a funeral home on the phone. After he gets off, he tells Laura, "How do you like that?! They have a layaway plan. You pay now, and go later." Nowadays, many people prepay for their "final expenses" without a second thought.
Laura seems like a fairly normal housewife now, but at the time it was apparently a big deal that she was regularly shown wearing pants. Amusingly, Lucille Ball, who along with her then-husband, Desi Arnaz, owned the studio facilities where The Dick Van Dyke Show was taped, had previously worn capris on her own show, I Love Lucy.
The level of sexual tension between Rob and Laura was also pretty daring at the time, though the image has now been completely eclipsed by their separate beds.
In the fourth episode Sally starts crying the day after a date where again her aggressive sense of humor and brutal honesty scared off her date.
In the episode "Where You Been, Fassbinder?", Sally is humiliated when the old high school flame she thinks is there for a dinner date turns out to only be there to sell insurance. Although later in the episode, things get sorted out and he *was* hoping for a date, but he overheard Sally talking about a made up boyfriend.
Values Dissonance: One episode had the Petries set Sally and one of Laura's friends up with the same guy, and both of them get frustrated when he doesn't make a commitment to either of them. When asked, he reveals that he takes it slow with dating because he's been married twice before- but they left because he used to hit them. He is portrayed as if this were just some little flaw. Rob and Laura don't react much to this news; comparatively, they're stunned when they hear he was married before — this also forms the basis of the fairly serious episode "Divorce" where Buddy finds out the same about Pickles, wants to leave her, and Rob sympathises with him completely.