Patience is Virtue In Poker!
Beginning poker players often make the mistake of getting sucked into the pot because he/she got impatient.
While there are some luck factor to Poker, it is mostly a game of precise math and odds calculation. You really have to take emotion out of the equation, and, ironically, know when to be aggressive.
Also, you must know how to read your opponents, and be patient when your opponents frustrate you. When you go all-in on a tilt, then your opponent has already won.