Who are you?

So I have noticed a huge amount of people doing this in SL it happens in RL too, but more so in a virtual world I think that allows us all to be  someone else if we so wish.  So girl meets guy and  little by little girl becomes all the things  guy likes.... if he is married in rl all the better, she becomes that ear he doesn't have, she becomes more understanding than the rl wife, she makes herself available at  the drop of a hat to be there to listen and commiserate.  She begins to like all the things he likes, music, clothes, movies, even real  time past times such as bowling or  fishing.  Yes guys do it too though not as much that I have seen.  Here's the thing, once you have given up being who you are  then  exactly just that who the hell are you?  It's no different than trying to change someone, if you change them then they are no longer the person you first liked are they?  Yeah I don't get it but then I am stubborn as hell and would rather be myself, saves time trying to remember which lies you told to who.