[HighStakesPro]

This is simply not true. Playing KK the way you did is not "unthinkable" at all. Having just one opponent is the BEST time to slowplay big pairs in this situation. If you are against two or more opponents, you pretty much have to raise, but againnst an EP raiser, while raising is still a perfectly acceptable play, slowplaying can be very effective. It will become even more effective when you move up to higher limits. Plus, when an ace flops, you can just check and call and will actually fare better than if you had reraised preflop, because it will be much less obvious what your hand is. If your opponent has a lower pocket pair, he will continue to bet it because you have shown no strength and may just be drawing or calling on middle or bottom pair. Reraising is a safe play and can't be criticized, but if you want to really get to the next level, you should try and vary your play somewhat and employ deception. If you always make the same plays with the same hands, observant players will be able to put you on hands.