And the other side of this coin: people who complain that the skills they were taught in school are useless just cause they don't use them on a daily basis. (Excessive knowledge, what a burden!)
It's like...maybe YOU don't use algebra, Kristy, but I sure do. And the whole point of math is to train you to think analytically, regardless of whether you remember a specific formula.
Personally, I never end up using my French (even when I go to French-speaking places, their English is so much better), but I still appreciate the glimpse at another language and culture while trying - however unsuccessfully - to make new sounds with my mouth.
Oh, and literature. I never analyze literature as an adult, so I guess reading all those classic novels was just, like, a total waste of time.