How often do you feel that you're changing?

This September I started to feel different(I didn’t realized this right than)and I started to change .I started with dropping a few annoying “friends” than I started to act different(I became more mean) with my relatives,friends and teachers.After a few weeks I changed my look and I started to hang out with a total different king of people(people which I found annoying before(they’ve changed pretty much too)).Now I ‘m having a total new way of amusement with my new friends and I’m having a passion(in secret) for a girl(one of the new friends)and I think that she likes me too but none of us has the courage to say something.The only thing that remained is Fluther and my hobbies(maths,physics etc),but I kind of became more good at them and I feel that I’m smarter and more profound now.
How often do you change yourself(even a little)?
What are the causes of this?
Do you think I should go see a psychologist?