Rodney

To a degree, a lot of people (I won't say everybody) do what you do, at least unconsciously. People pick up other peoples' personalities and adopt them temporarily all the time, in conversation and so on. If you stay around somebody else for a while, you'll note that they have widely different speech patterns when talking to different people. A lot of the time, they're imitating the other person (not all or even half the time, but a lot).

I don't know anybody who's tried to do this consciously. I never have. I have to agree with what you conclude, trying to do it consciously would be extremely exhausting. I suspect that you have an aptitude for mimcry that is above the average, and maybe also an above-average sense of empathy (not like you're necessarily a wonderful guy, but that you can read other people pretty well.) And you've developed all this into a skill at being other people -- that is, just like the people you're with. But like you say, it's hard, and after a while you have to wonder who "you" are.

Some people with these skills actually do well as actors. My wife, who spent some time in show biz, knew professional actors that didn't seem to have much personality of their own. They were so concerned with how others saw them -- it's actually what they need to do, in their profession -- that the "real" personality was hard to find.

If you want to find out who you are, I would suggest spending some time alone. What do you want to do when you're by yourself? Maybe a journal is a good idea -- after you're been with somebody and "been somebody else," write down what was easy and what was hard about being that person. What parts were good and what were bad. By a process of elimination, you may eventually be able to separate out the behaviors that you have that seem good and right _and natural_, on reflection. And that's probably you.