Don't take gravity too lightly, or it'll catch up with you.
Gravity is a harsh mistress.
Kyle Katarn in Star Wars Games - Jedi Knight: Mysteries of the Sith
Oh, no! Gravity is increasing on me!
Lilo Pelekai in Lilo and Stitch
Oh, gravity, thou art a heartless b*tch!
Sheldon Cooper in The Big Bang Theory - Season 1 Episode 2
12You see, madness, as you know, is like gravity. All it takes is a little push!