I went to high school in Las Vegas, so when I went to college everyone "assumed" I could count cards. After realizing it was a losing strategy to tell people that couldn't count, I looked up the basic strategy.

I wrote a computer program to simulate the game and the strategy and had the computer play hands until it was winning consistently. Generally it wasn't so much "counting cards" as it was "counting face cards and 10's, and changing your betting strategy based on that count."

Just thinking about the mechanics of a card deck, face cards, 13 card suits, etc. Turned out to be really useful in playing Bridge as well.