My background is in physics and I especially love the mathematics. My education is in physics, mathematics, computer science (programming) and Shakespeare from the University of Colorado at Boulder, but I enjoy most all of the sciences as well as many other varied topics. If I find something interesting, I don't just read about it, I study it. I used to go to the university and/or public libraries before internet days. Even with its massive amount of information, I still find the internet to be incomplete. Many topics are not detailed deeply enough, just the broad overview, although often well done. Wikipedia is often a great source. thankfully, because finding a library in my new location could be difficult as I now reside in a Spanish speaking country and am not yet fluent. So I order books that take 6 weeks to arrive, or often get the Kindle edition, but I prefer a book in hand to highlight and make notes in, or compare the information with another book, or review the maps... and I can easily flip to other sections--not so easy in Kindle.
I'm not sure what most people put on their user page; I just hope my (few) contributions in Wikipedia will be helpful.