I only use train spotters as an example because the term has now become generally accepted to describe anyone that is so focused and engrossed in his/her own interest that they are in danger of boring the ass off their friends and colleagues! People run when they see them approaching!
Years ago, I took a girlfriend out for a day in London. We used trains and underground all the way and ended up in Covent Garden, which is famous for the buskers, so we became busker spotters rather than train spotters. We saw a fantastic skiffle band called the Gutter brothers. They portrayed their skills using washboard as percussion, tea chest, string and broomstick as bass and of course the obligatory guitar for rhythm, they were raw and they were fantastic! That day I vowed to write a song about our experience, (after all we ended up getting wed) so far nothing, because my musical knowledge is so limited. I intend to put that right.
For the record, I think Alan Pollack’s work is exemplary and should be exposed to anyone with a genuine interest in learning.
I guess that “anorak” is the English equivalent of the American word “Nerd.”;)