I dont fold KK preflop in microstakes unless I get crazy action from like 4 tight players preflop. I am confident that folding KK in microstakes against less than a 3 way all in from 3 incrdibly tight players ahead of you is a leak. Over my past 15k hands, KK has been second most profitable behind, yup you guess it, AA, and I dont fold it preflop. Have I been stacked KK vs AA all in preflop? Yes, but I have taken more stacks from JJ, QQ, AK, AQ, etc. to more than make up for it, losing KK against AA sucks, but simply because it has happened a few times recently means nothing, you are thinking too short term.