Human Behavior Does a MAKEOVER

Recently one of my colleagues resigned from an IT Company. Everyone wished Good Luck except for a certain section of people. The idea behind this boycott was not clear. Was it the Pain and Suffering which they still wanted to infuse on the resigned person or the Pain and Work Pressure they (i.e. people who boycotted) would be experiencing once the resigned person is not available in the organization?

The thought behind this comes from a recent development which happened 2-3 weeks back. This colleague of mine is highly technically talented, works well under pressure and is a calm and composed character. Everyone used to seek his technical guidance from a trainee to a Group Leader. Before he resigned everything was cool, people were interacting properly, and things were working as expected. The work related discussions went to the extent of office lifts and facebook chats. But the day he resigned people stopped talking to him. They started behaving as if he had committed a murder. Even in the office lifts they behaved as if they don’t know him. I was literally shocked and later laughed with my colleague watching people behaving in such an abnormal way.