Still, I cannot imagine ever compiling Eurovision playlists.
Well it started small and snowballed... back in the day when I was downloading MP3s a lot more regularly, I got into the habit of downloading the official CD release after every show so I could listen to a couple of the ones I liked. This would have started 2006 maybe? After a couple of years I ended up just moving those songs into their folder rather than keeping the full albums, and it just went from there, year after year. Some years I'd add about a dozen songs, others it would be just 2 or 3. Stopped a few years ago in favour of just adding them to a streaming platform playlist instead - it's my girlfriend's preferred playlist when we're on a long drive somewhere due to the sheer variety, especially with nearly 20 years' worth of tracks.
We never watched Eurovision when I was a kid, my parents obviously couldn't stand it. I was aware of it and remember watching the '98 show after the UK had won the year before, but it wasn't until 2004 at uni that I properly watched the whole thing... and I haven't missed one since. I wouldn't say I know a lot about Eurovision. I don't follow any of the backstage news or anything, but I've got a good memory and there's a fair chance if I heard a random Eurovision song from the last 20 years I'd be able to place the year and the country, or at least get close.