Short bloke in a tall body

A colleague I always meet on Thursdays - let's call him Bob - surprised me again today, by standing up. For some reason I think of him as a short person, or at least not a tall person, but when he stands up he turns out to be tall. This means that every time he stands up I am surprised. I can't think of any reason for this. He's a perfectly normal guy - and a very nice perfectly normal guy - I like him a lot. He has plenty of personality and is often very funny, in a quiet, unassuming sort of way. (Is that it? Is it because he's quiet and unassuming?) He's about the same height as The Man, who is 183 cm and who looks pretty tall to me. I'm the short one. I come up to his chin.

A couple of weeks ago I was walking along from the station and a foreigner was in front of me. I didn't call out because the guy was tall, so I thought it couldn't be Bob, although the shape of his head looked familiar. That's funny, I thought. That guy looks like Bob, only taller.

Of course it was Bob, and of course I was surprised. I don't know how or why he got to be filed in my head as 'Bob, that short bloke', but the idea just doesn't seem to go away. I think he must be a short bloke in a tall body.