That's funny. My name is Kimberly (shocker!), and I get really irritated when I introduce myself as Kimberly and the new acquaintance immediately shortens it to Kim. I will accept being called Kim, but I judge people harshly who just assume that it's okay without asking. If someone takes the time to ask, I will usually explain that I prefer Kimberly, but they can call me Kim because I realize it's easier/quicker to say, and then I thank them for asking because most people don't. Truly.
DH's name is not an English name and he shortens it to a name that's more common and recognisable to English speakers. People assume it's shortened from another name that
is common in the UK and US and call him that. But that's not his name!
I was taught to always call people how they've been introduced, especially if they introduced themselves.
I hate being called by my first name and last initial. I don't know why, but it really irks me. I'd rather be called my full name (first and last) or first and middle if there are multiple people with my first name around.
However, my full name could easily be misheard as a more common first and last name so that's the name I say if I'm not sure I want someone to know my real name.
If they don't turn out to be creepy, I can always tell them they just misheard me.