Business or Coach?

What is in airplanes that make people get much more open than in their regular life?
For many years it happened to me that I meet people on airplanes and after few hours which you spend squeezed on a coach seat, with little room to move, you find yourself wondering , what was it?
How come this person (and sometimes you) opened and shared very intimate facts about herself/himself.
The best allegory I can give to this situation, is like someone is forcing you to stay in a pub (drinks are free) with another person for few hours and you can't move any place as. Another thing that probably influences your behavior, is the fact that you probably won't see this person ever in your life and if you do it will probably will be different.
I heard a story from a good friend (woman) of mine, who met, on a stormy night, when their flight couldn't take off, the guy she spent few years with, after the flight took off from Hungary to NYC.
What was funny in this story is that he was flying business and she was on coach seat and that guy left his seat on the business and moved to the coach one.
And that's take me to a conversation I had with my wife after my last flight (Ams. – Tel Aviv) , there I met a wonderful woman who amazed me by her sincerity, and openness. She told me very intimate things about herself, her family and much more (thank you E. for being so open). My wife was wondering why it doesn't happen to her any more…………..the conclusion was that she stopped flying coach and moved to business!! Its much more convenient, but less interesting. People in business are less open and much more distant………so wake up people (business flyers) be opened with your flight mates , you will that your flight is much more interesting