Seriously ... I am pretty sure this is what a donkey looks like
Ok ... really seriously.
First - I hate the term. Hell I want to beat the crap out of whoever came up with it. Its annoying to watch "adults" call someone a donkey everytime someone goes all in pre-flop, has the advantage pre-flop .... and ends up out of the tourney.
If you are going all in in a tournament you take seriously pre-flop ... you are the donkey. I dont care if you have AA, KK, or whatever. You have just given up any say so in the hand before you have seen even a third of the cards.
Almost every single flop you have ever seen is a flop where if the someone happens to have the right two hole cards - they will beat pocket AA.
I can not fathom how people think its some unthinkable thing that AA could lose ... it happens all the time. You see it happen all the time - its probably happened to you many times actually.
AA is the only hand that you can at least say its going to take some damn lucky cards to beat. Anything else you might go all in with ... its going to take one person staying with an ace (which is very likely the case if you have a caller) .... and an ace hitting the board.
Guess what - an Ace hitting the board at some point is going to happen more than once every three hands. Simple math. If you go all in with KK - you are praying you get lucky and it doesnt happen, or you happen to get really really lucky and hit another King.
When you go all in pre-flop... you take away the ability to see the board, see that there is an ace... and realize that putting all your chips in is a mistake. You also take away the opportunity to see the flop, see no aces - and then push and now scare out the ace.... that would have beat you when an ace hits the turn or river.