Some one is going to correct me on this but I think the odds of getting AA dealt to you is around once in around 120 hands, If you wait for these cards to be dealt to you before playing, your chip stack will dwindle down to nothing in no time.
It would be very nice to play big pairs all the time but when you spend more time at the game you realise AA is not going to cut it. You have to be more versatile in hands you play and with time and experience you can become very good at an important part of the game and
bluff!
Even if you were lucky to get AA dealt in every hand they only win 80% of the time, So going all in on the very first hand, could be the 20% they lose and it's Game Over!
When the fun Stops, STOP!