I had been using Windows forever but I had thrown up ProFTPd a few times on a Mandrake machine to serve up music on the local dorm network...
I knew the reputation Windows had and it was frustrating to use sometimes even when I used it primarily. One of the really irritating parts was having to reboot at the drop of a hat. By early 2005 I'd been using that FTP service for a year or so and I hadn't really gotten together the initiative to make the jump to Linux full time. Then I was reading one day and I found out about Windows Palladium and NGSCB and TPM enforced DRM and all the bullshit that was supposed to be possible with Trusted (Treacherous?) Computing. That was the straw that broke the camel's back. I went to the book store around that time and found a Fedora Core 4 book. It looked nice and I got it. The summer of 2005 is when I went cold turkey to Linux and I have never looked back.
The first thing I remember doing after really moving to Linux was setting up a network between my laptop in the living room and my desktop in my bedroom. I played music on my desktop loudly enough that I could hear it in the living room and I telnetted [sorry SSH
Since then, I've gotten more into it. I've set up software RAID and LVM volumes and compiled custom kernels and all that stuff. I've been using Slackware the last two years or so and I really feel comfortable. I have all the tools I need in terms of programming C/C++/Python (those are just the ones I use), serving FTP/HTTP/SSH/etc. , the RAID stuff I was talking about earlier (mdadm is a godsend)... I can even play a lot of the games I like under WINE (because the games I like are Starcraft and Diablo 2) (my gaming 'career' became stunted when I moved to Linux but my programming skills and knowledge of my hardware shot through the roof!).
I know this wasn't supposed to be some evangelical Linux thing... but I really enjoy and appreciate Linux. If I want to make backups of my hard disks, I don't go buy some expensive Windows software. I use dd or add the drive to my active soft RAID volumes long enough for it to sync and then remove it... If I want to modify or transcode audio or video, I don't go buy some expensive software, I use MEncoder. I don't go buy compilers, I use gcc and g++. I didn't have to beg the writers of kasteroids to make bullets last forever and fire more frequently, I downloaded the source and made them do that myself!!
Linux just allows you to control your machine on a level that's just not possible in Windows and I hate hearing about how Linux users "just don't like to pay for things." I can't afford to pay $30-$80 for some crap utility to convert gifs to jpegs. Why not just use GIMP? I'm not going to pay $80-$100+ for some utility to sync my drives when I could use a one line command to do the same thing (dd,rsync). It's like a bad joke.
I'm finished with my rant. Sorry for letting my "first linux experience" turn into "linux fanboy hour".