Herb - started out because I liked it...progressed into medical reasons. Not that I don't still LOVE it, but having the doctor tell you "smoke a few times a week, or get a spinal tap every 4-6 months for the rest of your life" I chose the obvious answer.
(edit: yes, that is honestly what he told me. The alternative medicine for my condition is frequent spinal taps and pills that make you want to vomit.)
Many people I know who smoke cigarettes started because they started working. People would go out on "smoke breaks" and eventually that turned into "hey, you want one?" which turned into "I'm gonna go on a smoke break" which turned into "I smoke to relax" which turned into "I'm gonna go buy a carton."
