COMEDY

'National Lampoon’s Vacation' features Chevy Chase in an idiot-defining role as the alarmingly optimistic Clark Griswold, a husband and father who is determined to give his family the ultimate vacation—no matter the cost to life, vehicle, or animal.

The comedy classic arrived in theaters 40 years ago today.

Mel Brooks's charming spoof, which premiered 25 years ago, extolled the virtues of form-fitting legwear.

The Dude abides. (Hopefully at a cinema near you.)

Comedian and actor Robin Williams helped the careers of his co-stars and kept everyone around him laughing.

One joke was so funny, an audience member literally laughed himself to death.

The 'Price is Right' host really doesn't need the glasses. He wears them just so you'll recognize him.

4. A scene in which Rowan Atkinson's character feigns madness by wearing underpants on his head and sticking pencils up his nose was inspired by Atkinson's penchant for sticking pencils up his nose.

No wishing on a Zoltar machine necessary.

Ethan Embry doesn't know, or care, what his character's letter said in the classic teen rom-com—which is turning 20 years old.

Fans of the show have spent years digging out jokes buried in the background, beneath the narration, within the soundtrack, and everywhere in between.

2. The scar on her face came from a bizarre attack that occurred when she was a child.