Having had a chance to experience Larry up close at a YAPC, I firmly believe he's one of the most quirkily brilliant people in the industry (for whatever industry means in this case).
I was 12, I have a video game in Perl I wanted to modify (Frozen Bubble), I only knew shell. I did not have an Internet connection at home so I had to boy a book. So I bought Programming Perl 3rd edition, which had recently been released. And I read it. Front to back. Several times.
I probably wouldn't advise anybody to start programming by reading 1000+ pages of Larry Wall's prose. I do advise anybody serious about programming to read that book sometime. It is not only a book about a programming language. It is a book about the essence of software, or rather Larry Wall's vision of it, hidden behind a book about a programming language.
If I write code for a living today, it was in large part thanks to Larry Wall.
Was a real treat. A real nice humble guy. I posted in r/perl at the time. He's active in #perl6 on freenode, I believe.
It's a shame that he's had health issues.