When I was young, I hated the name Omar. I could never find anything in stores with my name on it, and I didn't know anyone else with that name. As I got older, I learned to appreciate its uniqueness (in upstate NY, that is) and pronounceability. But to this day, I am still baffled by the reactions of people, particularly older people, when I am introduced to them. Invariably, one of three scenarios take place:

Scenario 1: Uncomfortable listing of every other well-known Omar
My dad and I are at the golf course. We get up to the 1st tee, and there is an older guy playing by himself. He asks us to join along.
Dad: I'm (name), this is my son Omar.
Old guy: OMAR.

Important Note: I forgot to mention, each of these scenarios involves people repeating my name at unnecessarily loud volumes after they first hear it. "Booming" is the term I would use to describe the voice infliction people feel they need to use when they initially say my name. Inexplicable, yet it happens 100% of the time.
Old guy: Omar SHARIF. Eh? (stares, as if waiting for a response)
Me: Um, no, Phillips. Omar Phillips. Nice to meet you.
Old guy: But you know him, right? Omar SHARIF?
Me: I've, uh, I've heard of him, but I don't actually know him, no.
Old guy: Omar the TENT MAKER.
Me: (polite smile, then look away and take some practice swings)
Old guy: Eh? How about him?
Me: Yeah, I've heard of him too.
Three holes later
Old guy: General OMAR BRADLEY. Eh?

Scenario 2: "Polite" Arabic Association
I work with college students. One day, a student comes by with their parents to introduce them to me.
Student: And this is Omar
Father: OMAR. Hello!
Me: Hello, Mr. (lastname). Nice to meet you!
Father: Or I'm sorry, I should have said a salaam alaikum.
Me: Um, no, 'hello' works just fine. Though the name has Arabic/Islamic roots, I happen to be American and Christian. My parents just liked the name.
Father: What is it that you're supposed to say in response to 'a salaam alaikum' again? Something like 'malaikum salaam'?
Me: I think it's 'walaikum salaam,' but again, I'm no authority.
Father: Ah, yes. So next time we meet, we'll have it right.

Scenario 3: "Impolite" Arabic Association
I'm going into a polling location preparing to vote. I walk up to the table, where I have to tell my name and address and sign the book thing.
Me: Name is Omar Phillips
Old lady: OMAR? Is that like Osama?
Me: Nooo... um, Omar. O-M-A-R. Last name Phillips.
Old lady: Because we wouldn't like it if it was Osama.
Me: (sigh. I proceed to start giving my address)
Old lady: (to the old lady next to her) His name is Omar, almost like Osama.
Old lady 2: OMAR? (looks at me) You're not like Osama, are you?