A friend loaned me a CD set of Mandrake which had an early version of KDE. I was floored away by something as simple as the level of customization you could do with the taskbar. And having this alien operating system running on an alien EXT3 partition format instead of FAT32 or NTFS that you didn’t need to defragment. It seemed pretty fantastical.
I loved tweaking the desktop environment on Windows by replacing explorer.exe with LiteStep and Blackbox so likewise I did this on Linux. Over time I had fun discovering Gnome2, Fluxbox, XFCE, etc. you name it. Eventually I got a desktop I really liked and felt productive on and as Windows XP approached end of life I had no intention of using Vista so I transitioned to exclusively Linux at that point.
I did play with different distros and running servers at the time, hosted VMs back in the day you had to take whatever distro they offered. But for my desktop I basically went Mandrake, Arch (didn’t know how to make everything work), Debian, Ubuntu, back to Arch.