about 20 years ago, after college, i worked as a bike mechanic. the other mechanic sharing the shop with me was a marxist. i was feeling righteous over various environmental issues and was increasingly becoming concerned with overpopulation. this fellow mechanic hooked me by saying something to the effect of "people like Rush Limbaugh are right about environmentalists, you know... they're watermelons... green on the outside and red in the middle...any serious environmentalist would see that a fundamental change in the economic system is needed." duh.
throughout the months we worked and biked together he happily shot down my tiny liberal counterarguments. learned a universe more in that shop than the four years going into debt in college.
then i hooked up with a 'reading group' sponsored by a socialist party closely allied with the IWW. There were some actual very old wobblies that hung out there, regaling us with stories of wildcat strikes. we read Daniel DeLeon. pretty one-dimensional stuff, but did re-enforce some of the stuff i had learned truing wheels.
then, in a different city, started in with Chomsky and Z Mag and more activitism. Through working on some housing issues i was recruited into another study by socialist group filled with great organizers and good people. read the manifesto, lenin, mao, gramsci.... but it was primarily the hard work and decency of the people in that group that sold me.
my mechanic friend and i still get together quite a bit. he's the environmentalist now, with marxist underpinnings. i'm the whacknut :-).