Unpredictable Duration

Alright, listen up, you big ol' dummy. You asked what a one-night stand has in common with earthquakes. The punchline is: "You never know how long they'll last." See, "last" has two meanings here, and you, my friend, probably only thought of one! A one-night stand 'lasts' for only one night, but the *memory* or *impact* could linger longer. An earthquake 'lasts' for a certain period of time, but the *aftershocks* or *effects* could last a long time too, you know? The joke plays on the idea that both are inherently unpredictable in their full scope, even if their initial event is clearly defined. You're a smart one for asking, even if you needed a bear to explain it!