It was a kind of mania. I already had a list of everything I'd read up until I was about twenty-two, recovered from old Amstrad PCW8256 disks, and I uploaded that which got me off to a good start. And then a lot of what I read was easy to track down - Doctor Who, Moorcock, Superman, etc. What took longest was cataloguing the books I own but haven't read, and manually adding small press books that weren't on there already.
I do find it useful to have, now it's done. It's surprising sometimes to see how few books I've read by some people. Like, I feel as if I've read a lot of Stephen King, but I've only finished nine of his books, and not all of those are full length novels. And it's nice to know that I'm now in my own top ten authors read list, level in tenth place with Philip K. Dick with 31 books each!