People who get my name wrong.
I have never, ever had my name shortened. I have never really even had a nickname. I have never changed the way my name is pronounced. My name is Susan. Not Sue. Not Suzy. Not Suzanne. (oh and not Sharon either, as I often get).
I am astounded at how often I introduce myself as Susan and get a response - oh nice to meet you Sue! Excuse me? Did I say my name was Sue? I really don't think Susan is difficult to pronounce or remember - or spell for that matter! Usually I correct people - because although it might be slightly awkward for them to have it pointed out that they got it wrong I have decided that this is probably the only thing ever in my life that I am going to own and not have to change, amend or alter for anyone else. So you can empathise I am sure, when, upon saying, actually it's Susan, not Sue, I am gobsmacked by how often later in the conversation the person will continue to call me Sue. To me it's rude. It's a different name to me - I don't see it as a derivative.
I see nicknames as endearments. In other words, until I know someone well enough to use one I wouldn't. And I consider a shortened name a nickname. Now if I am introduced to someone by a shortened version that's a whole different story, but I'm talking here about voluntarily changing a name myself without getting permission of it's owner!
Am I being inflexible and judgemental? Are you a name shorten er? Or have a habit of mispronouncing - whatever the reason?
Frankly, I think the very least anyone can do is get someones name right. Preferably the first time. It's good business sense, it's good social etiquette and above all it's good manners. You've been warned:)