Poker can teach you several things:
Poker should be a good math tool, teaching you how to calculate pot odds
, implied odds and most importantly your outs. In NL you have to be able to do the math in your head quickly to see if you should stay in the hand. I can cost you all your money or you can be shorting yourself money if you can't do it right.
Poker can teach you people skills. You have to be able to look at the people at the table and not only get a read on their poker skills but what type of person they are to determine their overall skill and get reads on them. You can play the cards or you can play the people when it is live. Both can work and do. It is a true skill to get the people at the table to talk and allow you to get a read on them.
Poker should also teach someone money management weather it be your your bankroll or your tournament stack. You have to know what level and how much you can spend. Do I want to blow my bankroll in one huge event or play a bunch of smaller stuff? I this is where the addictive personalities can get lost. They don't have the breaks to know when to stop.
Poker should also teach you to be a good sport. You win some you shouldn't and lose some you shouldn't. I think these two types of hands shows someones true character. Ego is a big thing in poker, if you don't think you can win, why enter the tournament? I would love to do a search of all posts and see how many people fancy themselves as below average players (bet it don't find many). Everyone fancies themselves as average or better which makes it oftly crowded at the top. If everyone in a 100 person tournament is of truely equal skill level, who wins? The one who gets lucky? So no matter what your skill is, luck plays a part and that is why it is called gambling. Don't showboat when you win and don't cry and get all pissy when you lose, it is called class and I don't see enough of it around in all sports.