that may be due to where they learned, I am doing a HND in computer science and we are learning C# and nothing else...
before i began i knew (well enough to make use of) C, vala and a small amount of lisp and PHP
Sorry, I wasn't clear enough. The guy didn't know that such things such as open source, git, Ruby, Python, Perl,... even existed. I find it impossible to browse the web and not to run into them, but it seems to be quite possible.
To the HN crowd, this is almost unbelievable, but it is not the worst I've heard. This summer, going on a vacation, I sat next to a working programmer who's knowledge of programming and the programming languages begins and ends with C#. He had no knowledge of Ruby, Perl, Python, open source, git, ...