I don't really remember how I came upon this site. But I love reading lists of things on the internet so it is a perfect fit. I must have found this site by 2008 at the earliest, but it might have been earlier.
The first big thing I did on here was expanding the Sonic the Hedgehog comic page, because I am a fan, I was bored, and I was procrastinating on something else. When I first saw it, it was like five tropes and a line of text.
For some reason one hot day in April in 2009 I got a wild hair up my ass and decided to clean up Hey Its That Voice. I sort of regretted it by the next day, but by then it had already started. The cleanup process took about a week spread over a month's time. The worst part was having to delete people's entries that didn't fit in with the new setup I had. Eventually I finished it and put the massive revisions on the page, hoping no one would mind.
I worked on the Excel Saga entry to make it more in line with the manga. Originally it just focused on the anime, but I added tropes for the manga, then split the pages when namespaces became more common. I also cleaned up the character pages and added better pictures.
But the project that really got me started on my current semi-obsessive page cleanup interest was the Dead Space page. I cleaned that up, made pages for all the tropes that were for different games or spin off media, moved tropes to character page and organized that. I separated the Headscratchers, Funny Moments, Awesome Moments, Fridge pages, Wild Mass Guessing pages, Heartwarming Moments, Nightmare Fuel, and Tear Jerker so that examples that were only for specific media went with that media's page.
That just set me off. A lot of pages, especially Video Game pages, had a lot of redundancies, and improperly placed tropes, or were abandoned entirely, and I cleaned up and organized a ton of them, especially the Emotional Torque pages, plus fixing the namespaces so when a trope page talked about a specific game, or whatever, the link went to that game. The biggest project was cleaning up Metal Gear, which did not anything separated into their own pages. That one had a lot of namespaces that need cleaning, and its Headscratcher pages were unwieldy originally. I also cleaned up Resident Evil, Parasite Eve, the Sonic the Hedgehog and Saints Row Emotional Torque pages. I still do it if I get into another franchise.
I also added Agatha Heterodyne to the Pantheon of Technology under Goddess of Steampunk Machinery and Hannibal Lecter to the Pantheon of Food under God of Humanitarians, back when trope page games were still a thing.