Before that (and being young and not exposed to anything else) viewed Microsoft's OS as the best thing since slice bread. I was able to code and do things with Visual Studio 5.0/6.0. In my eyes nothing could compare.
One day, my mouse pointer would slowly move down the screen without touching it. Thinking it was a virus or something, did a reinstall of XP. A few months later, the pointer was playing up, again.
There were other things but it was the start to my journey to GNU/Linux. I was barely exposed to GNU/Linux a year or two before but due to lack of internet at that time, could not grasp the change being a Windows user.
This time I purchased a book on Ubuntu and realised how cool this really is. It also made me appreciate programming. I no longer was 'clicking the play button' on Visual Studio. Now I was understanding how to compile with gcc.
Since then I would choose GNU/Linux over Windows most days of the week. The only exception is my job.
For example, I have one job that still uses legacy software. We are talking programs originally written in the late 90s in Visual Basic 6. I have to use Windows. Some program before I joined moved over to .NET and SQL Server. My goal is to move away from Microsofts tools. No more Windows Servers. Using (perhaps) Go, Postgres, etc. The Company would save a lot more money as well. Baby Steps.
I don't hate Windows, but I still have to install it on one laptop and the amount of stuff I don't want gets annoying!
Most of the time I am using Debian, both on my (other) laptop and as a Server machine.
I could say more but that will do.