Some ideas:
Strength of HS team - if
you're a really good player who makes all your points
getting the answers that no one on your team knew, then
you may not be as good as another player with
inferior stats.
Fear - Moving to college can be
quite frightening - instead of being a big fish in a
smallish pond, you're going against grad students or
seniors who say "hose!" or "gift!" or "buzzer check!"
after the one question that you might have
theoretically had even a chance to answer - if your team's best
player, who obviously has her mind linked up to
AltaVista, hadn't buzzed in after four words.
Burnout
- If you're a good player in high school, you
probably spent at least some time memorizing stuff -
possibly due to the fact that your high school didn't have
much else to do or your coach was sick of going
against Walter Matthau and decided to try qb. Colleges
usually have many more items competing for your time, and
qb may get pushed aside.
Team chemistry - If
you're a trash player at an ACF school, or if no one on
the team seems to match with you, you may decide to
part ways and join the Pokemon club to find others
with whom you mesh better.