Nano: "Sketch too big," 14,336 byte maximum. It used to be 30k bytes maximum?

Why will my Nano only hold a 14,336 byte sketch all of a sudden? It has always held the 21,000 byte sketch I'm trying to upload before.

I found the problem. Somehow the ATMega168 got selected in the IDE instead of ATMega328. That has never happened before. Thanks, all!