My official name is Efthymios Kallos. However people don't like this name very much and have been using different ways to call me. Especially when I came to the US the matter became so complicated that even I am confused some times. So here is a list of my names and which people use them.

Themos ["e" is pronounced like "ai" in the word "air"]:
This is how my close friends and family call me; my mother gave it to me because she thought "Efthymios" was a really bad one.

Themos ["e" pronounced like "ee" in the word "bee"]:
My housemate calls me like that. Don't know why.

Themo:
My advisor, because he's half-Greeks and knows that names in Greek do not have always a final 's'.

Themoulis:
My girlfriend is calling me like that.

Efthymios:
One of my professors calls me like that; I introduced myself to him like that since I wanted to have in mind the formal name I have in the homework sets.
Then he started calling my like that during class so all of these classmates and his research group is calling me Efthymios.

Efthymis:
An old guy in my home town calls me like that.

F3:
My roommate Rajay likes that name a lot (Efthy-->F3).

Efthymakis:
An old lady in my mother's home town calls me like that.

Kallos:
This is how people know me in the Kung-Fu class. I said both Themos Kallos when I introduced myself, but the instructor only kept the easier one.

Tim:
My name in Starbucks & the Tennis Club. For some reason people there did not understood Themos without saying it first for 4 times, so I had to switch to something simpler.

Johnny:
My name in clubs and bars. I needed an easy American name that Americans have heard before, because with loud music it's impossible to grasp
a name you've never heard before.

Tough Carlos:
The car-dealer lady calls me like that. The full details are in my blog: here