It's funny how you can stay friends with some people for years and years even though you only see each other a few times in that whole period.
Like Claudio, for instance. I know Claudio from about 10 years ago, when I was on a backpacker bus tour of the South Island. He was travelling the world with his mate John, both scientists living and working in Newcastle, England. John was the chatty, flirty one, so it's a little ironic that Claudio's the one who kept in touch over the years. Claudio and his new wife are coming over to New Zealand for their honeymoon, and so it's pretty cool that we'll be able to catch up. I'll get to see whether his taste in spectacles has changed, and he can ascertain whether I ever got my growth spurt.
Or Mike, whom I've known since my OE backpacking days. We hung out together for 3 days in Florence, then I stayed with him for a week about 3 years later, when I went to Seattle for a holiday. And after all this time, we still send other longish Christmas e-mails. Most likely we'll never actually see each other again, but it definitely feels like I have a good friend in Seattle.
That's a long way from to the "single-serve friend" referred to by the protagonist in "Fight Club".