Honing your card sense is a lifelong skill that appears to never fail to be useful. A good card sense for a table can tell you what starting hands to play and allow you to adjust your playing style to a loose or tight game. Your card sense for an individual player allows you to read them better, allowing you perform those psychic "I know what you have" gymnastics that make you a deadly card player.
Just for fun, I decided to try and develop my card sense on some old Omaha/8 sessions I had stored up in Poker Tracker Omaha. (There are also Stud and Hold’em Poker Tracker versions available. You have to go buy them!) I tried to forget everything I knew about Omaha/8, and just sat and watched my session. Who won the hand, and what kinds of hands did they start with? Without a doubt I realized that many times when I saw a flop and lost, it was because I had started with a weaker hand. If I had a better read on the player, or if I had a better read on the table, I wouldn’t have played those hands at all.
If I was an alien, I think I could almost learn how to play Omaha/8 well by simply watching the patterns of hands that won, and then only playing those hands, calling everything down to the river.
It was a neat experience, one I think I’ll try and repeat with 7 stud.