School bus and office bus

Today while traveling to office in the shuttle, we stopped at a traffic signal beside a school bus. It struck me that how much almost every kid in the bus was interacting with one kid or the other, while everyone was so silent in my shuttle. What is it that has changed its so much, as we grow up, that inhibits is from freely interacting with others. Maybe we know the answers but are not to open about it. We don't trust each other easily and sometimes it is difficult to do so because of the kind of experiences we have had in life.  But I think life in a society or community is worth living only if you can muster the courage to share some moments with others. Give others the power to hurt you and put your trust in them. Yes, you run the risk of being duped, but then I think we should always try and prohibit ourselves from taking ourselves to seriously. There have been billions of humans who have lived on this earth for all these years and the fact is that no one really made it.