* The ending of "Nuts to War (Part 2)" (where Earl tries to snap Robbie out of being a bloodthirsty warlord) is both this and a Heartwarming Moment.
-->'''Charlene Sinclair''': [after the war is over] I heard that somebody got killed.
-->'''Robbie Sinclair''': Yeah, it was some new guy... but you know we could've won!
-->'''Earl Sinclair''': Robbie, what're you saying?
-->'''Robbie Sinclair''': Well, I'm saying it's terrible that guy got killed and all, but you know we had those four-leggers on the run, we could've won it.
-->'''Earl Sinclair''': A boy died, don't you see the fighting didn't solve anything?
-->'''Fran Sinclair''': Come on, Robbie, let's get you out of that uniform, you have school tomorrow.
-->'''Robbie Sinclair''': Forget school, a bunch of the guys were talking about keeping the army together if they came back, they'll set up a base at the swamp so we'll be ready for them next time. They're working on a WHOLE NEW line of weapons, yeah!
-->'''Earl Sinclair''': Stop it! You're not a soldier, you're a kid,
-->''[pulls Robbie into a close hug]''
-->'''Earl Sinclair''': You're gonna go to school, you're gonna take girlfriends to dances, you're gonna drive me crazy like you always have, until it's time for you to grow up.
-->''[A small pause as Robbie comes to his senses]''
-->'''Robbie Sinclair''': Dad?
-->'''Earl Sinclair''': It's allright son, it's over... you're home.
* The ending of the episode "If You Were a Tree", when the tree is blown up by the dynamite.
* The final episode, especially the last five minutes. A new ice age is forming, the dinosaurs are doomed, and ''everyone''[[note]]except most likely the cavepeople, the mammals, and any species that survived the K-P Event[[/note]] from the series is going to die. But what really drives it home is when Baby asks what's going to happen to them. Earl and Fran don't say anything, but from the way they look at each other, it's clear that they know they're not going to make it. This comes with the unfortunate implication that technology is going to be set back millions of years, as the cave people won't become intelligent enough in time to save it, thus forcing them to reinvent it all from scratch over hundreds of thousands of years.
** The final words of the series.
-->'''Howard Handupme''': And taking a look at the long range forecast: continued snow, darkness, and extreme cold. This is Howard Handupme. Goodnight... goodbye.