On the one hand, I read over and over that a good humble attitude is necessary for low-time guys (eg first year F/Os?) because they have so much to learn.

On the other hand, there are whole threads dedicated to vehemently asserting that first year F/Os should earn four times as much as they currently do, presumably because they're worth it.

So they don't know very much, but they're awesome enough to command a good salary. Seems like a delicate balance.