Homer's brain: It's simple, just use reverse psychology.
Homer: Reverse psychology? That sounds too complicated.
Homer's brain: Alright, don't use reverse psychology.
Homer: Alright, I will!
Homer: Insurance is the greatest deal ever. If I get hurt, I get paid. And man do I get hurt!
Homer: Weaseling out of things is important for kids to learn. It's what separates us from the animals. Except the weasel.
Jimbo: Dude, you kissed a girl! That is so gay.
Squeaky Voiced Teen: We're out of Secret Sauce. Go and put this mayonnaise out in the sun.
Homer: I won't lie to you Marge... Well, good night.
Homer: You'll have to speak up, I'm wearing a towel.
TV Announcer: Coming up next, Carmen Electra stars in "Boobs", about psychology students and their teacher who wants to be take seriously.
Homer: Aw. I thought it was about her boobs.
Grampa: I already got enough doctors poking at me here and pinching me over here and grabbing me down here and jiggling me under here. And that's just the receptionist!
Homer Simpson: No matter how good you are at something, there's always about a million people better than you.
Homer Simpson: Trying is the first step towards failure.
Homer Simpson: Marge, it takes two to lie, one to lie and one to listen.
Homer: I'm in no condition to drive...wait! I shouldn't listen to myself, I'm drunk!
Homer: How could you? Haven't you learned anything from that guy who gives those sermons at church, Captain Whatshisname? We live in a society of laws. Why do you think I took you to all those Police Academy movies? For fun? Well, I didn't hear anybody laughing, did you? Except at that guy who made sound effects. [Makes sound effects and laughs.] Where was I? Oh yeah. Stay out of my booze.
Homer: Kids, you tried your best and you failed miserably. The lesson is, never try.
Answer: I'm not sure if this is the one you're thinking of, but an episode of "Ray Bradbury Theatre," called "A Sound of Thunder," dealt with a similar matter: a group of hunters travel back in time to hunt dinosaurs, only to find things have changed when they get back because someone stepped on a butterfly.
Xofer