He was muggle, obviously, and didn't look very interesting. Have you ever noticed how they all look the same? Dull and bland?
I asked him if he wanted to play, and we did, and I won. He was drunk, just enough to put him off his game. He bought me a drink and he asked me about school so I told him I had left school, because I tried talking about charms with a muggle last summer when we were here on holiday and she slapped me. I still haven't figured out precisely why, except I had forgotten that she wouldn't know anything about charms, but that hardly seems sufficient provocation. She could have just said.
So this time I figured I would avoid the subject.
Unfortunately, it turned out he was a school teacher, and he had to give me a long lecture on the benefits of education, most of which was complete and utter rot because I don't need NEWTs to work in the family business and I already have OWLs. Of course I'd never leave school before NEWTs, but I got to arguing with him and the next thing I know he's telling me about the beauty of mathematics, which seems to be a muggle version of arithmancy.
I felt sorry for him, because I pretty much agreed with him even though I couldn't tell him, so I showed him the calculation I did about making wands, only I pretended it was a calculation having to do with astronomy, because he was just a muggle and wouldn't know any better, and even muggles can see the stars.
I made up a very logical rationale equating the length of a wand with the distance between stars, and in fact when I have time I'm going to work it out further because I think there might actually be an equivalence that might help in choosing a wand that suits a person. He got very excited, and wrote down a very simple equation, E = me2.
I told him it didn't look very interesting, and that my equation was much more complicated, and he asked me if I recognized it, and I said no. He became very upset, and gave me a very earnest lecture on things every schoolboy should know, using the blackboard where they usually write the specials at the pub (we had been writing on napkins before). Apparently, it is very important to muggles that every schoolboy understand that light travels very quickly but has finite speed, and nothing can travel faster than the speed of light.
It ended when one of the pub workers came over to rewrite the specials, and they started complaining about kids these days who had never heard of a man I had never heard of, and I slipped away.