Is it a habit for us to get influenced by our friend?whether it is good or bad

Hi guys!
Last time,I got a long lecture..wait no...scolding from Aidan...
He told me that I always try to fit in with other people...
I don't actually have many real friends though since I followed his advice....
That actually means that not many people are like me...
Then it came across my mind"Do other people also do what I did last time?"
Well,the answer is YES!!
It is proven theorically by me that other people also try to fit in with their friends..
For example:
-I used to have a friend who was always so timid and quiet..used to..
Eversince a girl who shall remained unnamed..well,let's just call her Claire..
Eversince Claire(a pretty and super arrogant girl) came into our lives,you have no idea how my friend changed...Now,she is so noisy..she looks innocent on the outside but inside she is really really a devil-like girl.As the saying goes"Never judge the book by its cover"