Is there a name for this?

It's been a while since I've posted. I feel like I've come a long way and every day I have moments where I realize how utterly insane my life with N was. I've moved past many of the bad feelings and am now working on figuring out how I fell for this guy.

One thing I just realized was that N was a master copy-cat. He would take on the hobbies and interests of whoever he met in order to make himself look more interesting. For example, before he met me, he bought a boat and convinced himself he was a sailor in order to look good to a certain group of friends. When I met him, it was clear that he was not very secure on the water and he had no interest in maintaining the boat. He just wanted to go to parties that his friends with boats had. He got angry that his friends wouldn't come and work on his boat for free and eventually sold it. He bought tons of salsa dancing videos and went to classes when he was with the girl before me, yet I know he has no interest in dancing. With me, he signed up for yoga when I did yoga and started running because I did (and I know he doesn't like either). One of the things that attracted me to him in the beginning was that he seemed to like being with my kids even though I knew he did not like or want kids; I was blind to that then, but I see it now.

Is there a name for this behavior? Is this a behavior that is common for N's?

thanks,
bluebird (slowly starting to sing my song again)