Eaves dropping on the train

For spring break, my boyfriend and I took the train to Portland, Oregon to visit a good friend of ours. I found out the train is one of the best places to eaves drop on people and with 12 hours to do that I heard a very wide variety of discussions.
The cutest by far was the little girl that was probably about 3 talking with her parents about people on the train. She noticed that there was a family that was sitting in front of that and pointed out that they had a mommy, a daddy, and a baby. Then she turns to her parents and said, I have my family too, see, my mommy, my daddy, and me the baby. Then she paused and goes and we have our diaper bag. We are a family.
It was absolutely adorable, and anyone that cares for or has children knows that the diaper bag is what completes a family :)

Another conversation that occurred was between the guy sitting across from us and the man sitting in front of him. They started the conversation when the train attendant told them that if any couples or groups got on the train over the next few stops they would have to be moved to the back with the singles. As the attendant walked away one of them laughed and said well its not my fault my ex was a cheating whore and now I am single. They both chuckled and turned back towards the front. Then after a while the man that had made the first remark broke the awkward first words of a conversation and asked him where he was coming from and where he was going. the second man answered very honestly, explaining that he was coming from Portland to Havre , Montana to see his brother and fiance. His parents were making him do it and he was pissed because his brother was whipped and his fiance was a brat that didn't like her fiances brother.
They talked so openly and exchanged stories like this for almost an hour. I didn't realize right away but near the end of their conversation realized that they had not even exchanged names. How is it that people can feel so comfortable with someone even if they just met. Are we able to connect that well with strangers because we don't know them? Does it feel comforting that someone knows our deep dark secrets but we will never see them again? What is it about strangers that give the us the strongest feeling of connection?