I think the biggest mistake that is made with this frame of mind is not learning how to properly read board texture and how it relates to your hand and more importantly, how it may relate to your opponent's hand. It is easy to be caught up in what cards you have and get excited with no regards to what your opponent may have. In fact, there was a time when I did as well.
One of the problems I think many players have when playing poker is being too two-dimensional and by that, I mean they don't tend to look at anything but their own two cards and their chip stack. Online Poker » Poker Strategy » Texas Hold Em » Board Texture