I finished writing my biology notes in 2006, and chemistry notes in 2007. Sometimes people ask me why I wrote them; for me, writing the notes was the way I studied. I do believe in that old (oft-misattributed) saying: If you can’t explain it simply, you don’t understand it well enough.
I initially just uploaded them to BoS, as an act of charity I suppose for future generations, but then the site was hacked and people could for some reason no longer access them. I started the site back in maybe 2011-12, and it’s been up ever since, initially on the old domain, and now this one.
The notes have spread like wildfire over the years, and I’m very proud and happy to have helped a lot of people.