It's interesting how in Germany there is so much accent on titles. Every country has their own interface standards and it is always educational to dig in to that for a bit to get acquainted with the local customs so you don't end up making some kind of faux pas. And sometimes those standards are very fluid, someone calling you 'Sir' may do so in a mildly sarcastic manner to get the point across, they don't necessarily believe you to have been knighted. And some people use access to their given name(s) as something to be granted explicitly, even though the company phone book spells out their first name and others are equally offended when you address them by their family name.

It's a minefield!