When we lose we remember those times more than the times we win because they are more unexpected. If you create an unbiased study with all of the results you might find that they even out over time. For instance every time you are dealt KK and are facing AK keep a record of all the times you lose... but also the times you win. KK loses to AK about a 1/3 of the time. So it isn't that unlikely. Think about rolling a dice. How often does it land on a 1 or 2? It isn't too unlikely. Well KK vs. AK is the same. Here I built a diagram that you can write out and make into a trial table:
---------KK--------QQ---------JJ
AK|
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AQ|
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AJ|
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Good luck
Also, because other people have folded they are less likely to be holding aces in their pockets so they are slightly more likely to pop up on the board.