My early brush with a genuine bubble caused me to formulate some guiding principles that carried me through the next 50-odd years:
It’s not what you buy, it’s what you pay that counts.
Good investing doesn’t come from buying good things, but from buying things well.
There’s no asset so good that it can’t become overpriced and thus dangerous, and there are few assets so bad that they can’t get cheap enough to be a bargain.