That Not So Funny Feeling

You meet someone new, either one-on-one or in a group situation. Almost immediately you get the clear sense this person has a visceral dislike for you. What happened?

It's possible some of you have never had this experience. I have, more than once, and do not believe I've been paranoid, clinically or otherwise. Further, I suspect my experience is not at all unique. When it occurred again not long ago, I wondered - what just happened? Out came my journal and, as is often the case, any answers I approached were rapidly superseded by additional questions to myself. Any of these ring a bell?

What did this situation share with similar situations from the past?
How much of the other person's reaction to me could simply be bad chemistry?
What part did I play in helping create that chemistry?
How can I learn from this?

Of course, it's unrealistic to expect everyone we meet will like us. In my case, with charm not being a strong suit, I would be delusional to have that expectation. Still, I'm on the lookout for patterns in these situations to help me reduce future incidences of that not so funny feeling.