a lot of people always limp Axs, suited connectors and even Kxs when they get the chance. So flushes happen. Quite a lot. And i've been on both ends of the flopped flush pain a few times in less than 100k hands. Happens. It's hard to fold weak flushes, sometimes it makes sense though. I'm stoked cos I folded AA on the flop today, and it was a good call...