You did nothing wrong. I made the same move in a 10-25 NL cash game with my KK. Had KK under the gun, made it 200 (8x the big blind!) to go, got reraised by the small blind to 600, in my head with good players at this table, why would anyone with aces reraise me in this situation when everyone folded around to him and the big blind? I immediately put him on queens, or even jacks... the situation would have been heads up, and he'd most likely make more by trapping me with his aces than he would by reraising me, where i'd potentially fold. After that thought process, I went and moved in for about 9200 only to ... yes face a pair of aces. I may have lost that hand, and my whole bankroll, but I did nothing wrong. I believed he held a hand lesser than mine, just turned out to be wrong. It happens. Now, what if he was holding AK? Then I have the best hand and it'd cost him his whole stack to peel a 3-outer to beat me. To the original poster, you did nothing wrong. AA vs KK .... simply happens, but hey, at least it didn't cost you over 9 grand like it did for me.
Also - your friend is right, yet wrong. You have two outs to improve your hand, but if your opponent was holding A/x he had 3 outs to MAKE his hand. If he's holding aces, then YOU have 2 outs to MAKE your hand.