Here's an example I'll give you.
So yesterday, the bride got her hair and makeup done at the Salon. I went there, introduced my self to the bride's mother, her friends, and chatted the bride up a little bit, but really about how great the weather turned out since it was supposed to rain, and maybe reviewing the schedule, etc. Otherwise, I was shooting. Pretty standard stuff. Went smoothly. But the thing is, I was there for about 2.5 hours and felt odd just being a fly on the wall and not talking too much. Almost like I was some kind of a hermit. 
Anyways, after that, I went to the Hotel to shoot the groom getting ready. Same deal. Small chatter. He was camera shy, so I kinda kept to the corner and just shot a few photos then went to the bride's hotel room.
The bride's hotel room was packed with her friends. They were watching TV, sipping on some champagne, and was generally having a good time. So I walk in, say hi, but then I completely shut down chatter because I had about 30 minutes to get some details shot like shoes, dress, jewelry along with some candids, and honestly I felt like I was the photographer, not a friend, so I shouldn't be obtrusive anyways. Again, maybe that's an excuse! As most of you know, time pretty much flies, especially when you are stuck in a small hotel room full of people with no where to place the dress, etc, etc. So I go about my business, just pretty much remaining silence, shooting photos, until she's ready to get into her dress. I give her instructions on what to do with regards to calling me in when she's in her dress. Then I come back in, shoot some photos, and we are on our way to the ceremony location.
That's a typical session for me.
But then I've worked with other photographer where they would be put in a similar situation and BAM...come in, immediately create a presence, have all the ladies laughing, smiling, etc. I look at that and say to myself "Damn, I want some of that". But that's just not "me", you know?
Anyways, when the day ended, the bride thanked me, gave me a hug, and I shook the groom's hand. Told them congratulations with a big smile as I usually do and went home. Again, that's a typical way things turn out for me.