My Korean classes have been derailed

So I have been trying to learn new Korean phrases from colleagues, and in the middle of one meeting (all in Korean of course), I attempted to pick up key words. The words I picked up either are not common or I misheard them. Our senior manager said he needed to fix the words I was learning ;)

I was given a new word, an actual Korean nickname. An KoSong (which means something like Maestro or Big Star). The funny thing is that An (a Korean last name, which correlates to Angus, and friends of mine) also means Not. So I either have been complimented, or insulted ;)