To continue to beat the dead horse, I resolve everything to human nature. There are some very basic reasons people are motivated to do better or more tomorrow than they did today:
Businessman- power (self determination), greed, recognition, money, fear (total loss/humiliation) , etc..
Laborer- money, security, fear(termination)...
Fireman- recognition, *wild-card*
Teacher- I got nothing, I mean seriously...maybe shame?
*wild-card: This is something that I could not find the words for. It's that feeling inside of not wanting to let those around you down. You'll find it most in soldiers. You'll also find it in policemen and firemen. When a soldier runs through enemy to help a fellow soldier he isn't doing it for money, security, fear, or any of the other reasons above, it's unique. I would almost call it love but that's not right either as a fireman will run into a burning building for someone they've never met. Anyway, those are the extreme examples of the "wild-card" motivator. You can find them to a much lessor extent that you would almost confuse with competitive-spirit (say during training exorcises). Oh well, hope that didn't make sense to only me