Basically because of video games.
It first started with doing some admin work for a very early online StarCraft tournament. Keeping the roster/grid up-to-date and posting results ... by literally editing the html file. Started out helping out more and eventually got into PHP code of this early tournament software and helped with that.
Then later it turned into writing scripts and addons for World of Warcraft, as well as just hosting the general infrastructure like forums, dkp systems and voice chat servers you need for a large guild. Even later external online tools for EvE Online (D-scan parsing, wormhole mapping).
Then I just got lucky and while telling someone all of these "qualifications" they basically just hired me. Even funnier, over a decade later an old WoW guildmate approached me with a programming issue ... and after solving it he offered me a much better job. That's were I work now.