Once Playing A/A I went all the way to the river with what I believed was a Full House when the flop came A,6,6, unfortunately I had A/4 and he beat me playing 6/7.
Mistake's are quite easy when you get into a hand, mainly because I do not like to look at my cards a second time, once I decide to play them, I will look at them once, memorize them, and play until the river or I fold them, looking repeatedly at your hole cards is usually a sign of weakness I don't want players to pick up on, so I avoid doing it.
I always play with a 4 colour deck these days when I play on-line so that I don't miss a flush hand, It takes a while to get used to seeing 4 colours but I don't mistake them any more, The only problem now is, Is my flush bigger than my opponents flush? Even hitting the nut Flush hand with the ace in your hand can be beaten if a straight flush is possible after the flop, turn and river cards are dealt.
Even a full house becomes a possibility if the board pairs at any time, so playing careful or trying to trap your opponent, can backfire on you.
When the fun Stops, STOP!