I've argued before to people that I don't believe true altruism exists.
Here's my latest case in point: I've started volunteering. Now, volunteering is a very giving sort of thing to do, innit? The giving of time and energy in exchange for no monetary gain? Yet I myself know that my reasons are anything but pure, and I'm fine with that. I know I'm no Mother Theresa.
Reason 1: I have no library experience on my resume but would like to transfer into that line of work. I have no way of going up against people who have either the relevant degree or experience--so I need to get that experience in some way. You can't gain paid experience in a job that demands experience to get into it, so I had to find another way. Enter volunteering. Two afternoons a week, for a few hours, I shelve books or do other tasks that may need doing.
Reason 2: I like doing it. I love putting books and materials to rights, to seeing the rows of neatly lined up items tidied by my own hand. I like feeling productive and efficient, seeing the cart of unshelved materials dwindle down until it's empty, knowing I did that. I only work part-time and am searching for full-time; in the meantime, not too many productive activities occupy my time, so having something constructive that gets me out of the house and away from the computer is a bonus.
So there ya have it. I'm a selfish volunteer.