I really have to wonder...

Is it a bad thing to be concerned, worried, troubled...whatever...over a single word?
A friend of mine said something to me a few days ago...and just one single word really bothers me...
I'm pretty sure she said it jokingly, and in reality, in the huge world we live in, I know its not true. However, in the context, and in my mind, I think she was trying to say something. Solely in the specific context, I'm starting to think that its true...despite the fact that I know it really isn't. This, among other thing has bother me so much that I have actually changed a few things-I'm rethinking one f my college choices, I've reverted to coin flips for deciding some things...its even gotten me to rethink my carrer path (it, and a few other things, see my comment to G-G's blog entry "Ego") and all of this over what? A single word? Honestly? It seems so stupid, but it's really happening. The worst part is that the person who said this to me is someone who I know is smarter than I am, who seems to do everything...and whose words/opinions I highly value, for many reasons. But still, this single word is really wreaking havoc on my thoughts, my brain, my everything...and I can't quite figure out why...

Is it the word itself that I am stressed over, or the context, or maybe even the person who said it...I just don't know...

I have never really doubted my-self, my abilities, my anything before...maybe regretted some decisions, wished some things had gone better...but nothhing like this. I just can't seem to get it off my mind...I mean, even at the time, I didn't think much of it. It was only as I was leaving the school from Math-Team (where it had been said) did I realize what had happened-what she had said...no...wait...what she had called me. If you have any advise-helpful or otherwise-please leave it in a comment or PM me...but I just don't know anymore...

P.S.-Yes, I do love being vague, its a specialty of mine...or is it...I just don't know anymore...I really don't...