Offices are like mini-families. Most of us spend up to 11 hours a day in close proximity, sharing the same office space, facilities, break rooms, refrigerators, coffee pots, etc, with our work colleagues.
Everyone shares responsibility for making the company work, run smoothly and stay profitable. Keep aside about 15 minutes a day to take a round, greet all the people you know with a smile and exchange pleasantries.
A smile and a warm handshake can wear off the stress most of us go through. Besides, making this effort adds to your desirability factor at work. And, even though it is considered a cliche, do remember smiling is contagious.