My first Linux distribution was Slackware 2.0, I used a myriad since then, subscribed to Linux Journal during its first decade, eventually as UI/UX developer I re-focused on Windows as main OS, although I still run Ubuntu on my travel netbook.

So I do know my way around Linux distributions.

Tweaking Linux is something I still have to do occasionally, like hacking around video acceleration, handling OpenGL rendering problems, or connecting to wlan routers.