I mean, the difference may not help you if you don't care about having that information available to you in the long run. However I'd posit that:

1) It's always nice to feel smart, and if you do it right you can remember these things for life

2) I'd rather know something than have to look it up online

3) Even if it's not directly related to what you want to do, doesn't mean the knowledge might be not come in handy one day.

Oh, being a musician totally converted me to the idea that practice will get you nearly anywhere. It also makes me somewhat tyrannical about it, as in "You don't practice every day? Well what do you expect without work! Success?!?!" I've always been thankful for that though. It helped teach me self-discipline and see that hard work does reap rewards, and the way to do it is hard work, every day.

Personally, I found it a lot more difficult to care in high school than in college - but in college I seesawed a bit and went the other way into "crazy grade-obsessed control freak," which ultimately didn't end prettily either. Don't go overboard. I think kb mentions that below. But you know. Caring is good. If creepy.