Flop raises span a range from total bs to 'you're screwed, i just hit my set.' The drier the flop and the more straight-forward or passive the villain, the more likely you're beat. With a wet flop, up against a tag or lag, you're often still ahead.

With AK, when you make TPTK, you are looking for three streets of value, but that's with villain calling you down. When you get raised on any street, you have to look at the total situation and decide if you want to go broke. It is not automatic to stack off with TPTK, even when you have AK.