Conventional wisdom is not always so wise. Sometimes, people are collectively crazy, socially stupid. We just notice what others are doing and thinking and we figure that if we go along with them, we won't go too far wrong. They, in turn, think much the same as they look at us. There we all are, copying each other, yet none of us are truly thinking. You can't base your most important choices on some norm or standard that everyone subscribes to but nobody understands.