I've been a Linux user for quite some time - I started sometime in 1998 with SuSE Linux as my primary operating system, but even before that I had seen other Unix derivates such as Solaris.
My first computer was an Amiga 600 (back in 1992). I liked AmigaOS, it featured a shell and was a fun playground for 9-year-old me. In 1996 we got our first PC, and until 1998, I used Windows. Compared to AmigaOS, this was clearly a major downgrade. You could only click on things, instead of being able to actually speak with the system. It was horrifying. Retrospectively, I cannot understand how I managed to stay a Windows user that long. Probably I just didn't know there was something far, far superior.
From SuSE Linux I went to Debian, Gentoo, Arch Linux and since 2011 or so to Ubuntu - because it "just works", and I can spend more time on everyday tasks when I don't have to spend time just fumbling around with the system. Ubuntu provides the power of any true Linux system, and works flawlessly anywhere and without investing any work. That really convinced me.
As a Linux enthusiast, I enjoy helping out new users of this great OS, and AskUbuntu is a great platform to do that.