Psychology of Passion/Teaching

People often do things in order to get repayment from someone else. We only live for so long on this earth, there are only so many diverse experiences, and there are only so many raw resources. And hence trading one of these for another is what our society is built upon. The intrinsic value of each of these changes from person to person based on their age, their passions, and a raft of other things to do with their past experiences. Many are the reasons for which we force ourself's to do what we do not like. As depressing as that is, I think it's nicer to look at the other side.

Why do people do things they love and for no payment? Does there need to be a reason? Can this reason simply be, because they want to? Why do these passions fade so often when they are self driven?

Alot of the answers are personal, so I wont answer them for you. So instead let me tell a story about an experience which I am battling with currently.

There is a new dev, I am trying to train them up and teach them what they need to know to do the work. I think this is in many parts an obligation; to reinforce the business... but my methods are a passion from me. A desire to show them more than what they need and grow them. I hope through showing this extra effort I can repay some past mentors for showing me something interesting or useful; this nurtured my passion and made it easier to work. Without this (for me personally) it really isnt exciting to teach. You get the gratification of seeing someone grow, but you dont have the fun of talking about something you care about expressively and informatively. Maybe this is selfish and is just a desire to look intelligent, gather admiration and trust. Bolstering my fragile ego is a sad excuse for passion, however it is hard for me to tell which it really is. Maybe a bit of both, which makes me question whether my future ventures in this regard are affected by failure here. I have trained others in the past with the same passion and they are now gone. Whether or not I failed probably is up to the student. Looking at it laterally, having this form of training with someone might instead attach them to you in reliance. If I was really doing this in good grace, you want them to be valuable and independent without you. However it is something I care about and will be patient until the day comes where something changes.

Maybe it revolves around both giving and recieving as both the teacher and the pupil. Mum and Dad were both teachers, but I have never asked their methods or passions.