My first mac was a Mac Plus, I started using it at age 5 (around 1987) My parents brag that I knew my way around it before I knew how to read. I used macs up until around 1994 until I switched (not the good kind) to PC. Now I just got my first mac since about a month ago (15" Powerbook 1.5) So happy to be back!!!
ran virtual PC for about a 1 year then made the complete jump and never looked back.
My parents ask me to take a look at their computer once in a while when it has problems, and sometimes when i need to test out something against a windows browser -- at school in the library they have windows, but when i need to run a computer i try and hit the multimedia labs and use the macs
My university paper runs macs so when i upload my pictures to the network after an assignment i'm always interfacing with a mac
generally most of the prof's at my school run macs as well --- i try to avoid using a Windows machine like the plague
I've been with Apple since 1986 - hard to believe it's been 18 years already. My first Mac wasn't actually a Mac either - it was an Apple IIgs. Great computer, that - especially with System 6 on it. It was painfully slow on the drawing part of ClarisWorks, however.
EDIT: I would have started in 1984, had I not been 2 years old at the time.
1996 with a Performa 6400 and still runs fine today, wakes up at 7am and sleeps at 10pm everyday waiting for someone to send it a fax or occasional use as a word processor. Been replaced in every day use by iBooks and a Powerbook.
Since I went to the Highschool and got into a class where we use macs or when I bought my first Mac computer (2 weeks ago)... or actually it was before then if you don't count the high school when I started using Basilisk II.