Years ago I emailed Joe Armstrong about concurrency stuff. I had no idea about anything like multithreaded programming or distributed systems or anything like that, but I had read Erlang was a language well-suited for that stuff.
I sent an email asking some seriously noobey questions about concurrency (about why mutation was bad, what made the Actor model work, etc), and instead of a response like "Go read a book and stop bothering me", he responded back with an incredibly long, well-written email explaining a lot of the minutia of how Erlang avoids a lot of pitfalls and generic concurrency theory. He was really good about explaining things in a way simple-enough for me to understand, without coming off as patronizing or rude.
About a year later I got a job doing Erlang, and I sent him another email telling him this, saying something to the effect of "sorry for bothering you a year ago, but your email was really helpful to me".
His response was basically "You have nothing to apologize for! I've always thought it was important to help people asking questions, especially early in their career".
I can honestly say that his kindness and patience changed my life for the better. If he hadn't held my hand a bit to make distributed systems make sense to me, there's a very high likelihood that I would still be writing Flash applications for a Tae Kwon Do studio.
RIP Joe, you will be missed.