I second Zen Scanner on the intense vibes thing.
I used to wonder about the pull-back from people when I'm passionate about a topic, but have since realized I also tend to raise my voice, gaze intently, and also gesticulate in a jerky manner. (I feel the topic, so this comes naturally.) Now when I find myself becoming overwhelming, and see the beginning of pull-back, I take a deep breath, look down and forcibly will myself to R-E-L-A-X. I've discovered by just doing this it gives the other person some sort of "psychic space" and often they will continue the conversation.
I also have learned to smile more! When one is smiling, one is not dominating the conversation. I find that alone makes others more comfortable.
You may enjoy reading these blogs of Rajesh's and others he has written about smart people.
7 Reasons Why Some Smart People Criticize Others 7 Reasons Why MANY Smart People Have Trouble Communicating Their Ideas
