I first discovered Sheldon Brown a number of years ago. I had an obscure bicycle problem and someone suggested Sheldon, because, "He knows everything". I assumed that meant he knew a lot about bicycles. No, he knew "everything". Everything about a whole lot of subjects. He reviewed a movie every day, various books and plays, sang in musicals, repaired cameras, answered 200 emails a day, took photos, read voraciously and wrote. He was a funny man with a huge, quirky intellect that masqueraded as a bicycle mechanic. I bought a bicycle from him and over the years we discussed (argued) about everything from Mark Twain to the morality of the military draft (he was wrong). Even when he was defending a shakey position he was always rational, thoughtful and courteous. If you were going to argue with Sheldon, you had better have your shit together.
He fought MS for last years of his life. From his THE BRIGHT SIDE OF MS:
"There's nothing like not being dead to improve a fellow's outlook!"
He died early last year from a heart attack.