Best lines in a song

There has been a long-running thread here of 'Best quotes' but maybe it would be interesting to find out folks' favorite lines from songs. To keep it on some sort of track, let's have a few ground rules.

- Attribution is required, who sang it (or wrote it) and where can we hear it?
- Shorter is better, four lines maximum, a verse. These should be words of wisdom that can be summoned for inspiration in social emergencies.
- If you're an opera fan, you're welcome to post in Italian, just don't expect many high fives from the monolingual among us.

I'll throw out a couple for starters:

When you're rockin' and a rollin' you can't hear your momma call.
Little Richard - Good Golly, Miss Molly

All I want in this life of mine is some good clean fun.
All I want in this life and time is some hit and run.
Little Feat - Fat Man in the Bathtub