Drifting apart

It seems to me that i've been there and yet not there for awhile now. I can't help but to feel that i'm drifting further away from my peers at work, not all of them but most of them i think... Could it be due to my boss or it is just me? I'm getting more serious and less idiotic lately, and the more serious i am the further apart i feel. A colleague of mine used to chat with me a lot but lately we hardly speak to each other .... and this symptome seems to be expanding to my other colleagues, one by one... Is this my fault?? Sigh .... I guess i'm bounded to be Mr Lonely ...