The convert's identity becomes so tied up with the group that their pre-cult life becomes hazy and insignificant to them in a very short period of time.
I very recently asked my wife point blank this very question....... whether or not being a JW would be the only thing by which she defined herself. She initially said that that was the most important thing, but, tried cleaning it up a little when I pretended that I didn't hear what she said and asked her to repeat it.
I think she knew exactly where I was going with that question..........."right out the door".