And it has. It's a difficult question to answer, but I'd argue we'd likely be a very different person. We often don't think about it (or, at least, most of us likely don't), but much of what makes us "us" is not solely in the mind (or brain, for that matter). Hormones have a huge impact on our moods, desires and social connections. Testosterone can increase aggressiveness, anxiety and libido. Oxytocin helps build and maintain emotional bonds and relieve stress. Certain medications (many of which seek to "balance" these hormones) clearly have an effect on personality. People often say things like, "[i]Grandma is not herself when she's off her meds.[/i]" I think it's safe to say that a new body would have, at the very least, an equal effect. Beyond that, we often make a strong association between who we are and what we (are able to) do. A successful surgeon requires steady hands. Their new body may not perform as satisfactorily as their old one. Put a basketball player in the body of said surgeon and he/she may lose many advantages their old body once possessed at his/her chosen sport. This could lead to a loss (or at least partial loss) of identity. Who we are is also largely influenced by how others view us. Ignoring the physical difference, the shift in your personality (from hormones) and physical abilities would likely lead people to treat you differently. If you went from being an concert pianist to a construction worker with tough and calloused hands, you'd probably lose much of your ability to play and people would likely view and treat you differently as a result. Being the incredibly adaptable creatures we are, we'd likely make subconscious adjustments in how we view and present ourselves. This brings up another question. What makes you "you". If you think you're a honest and shrewd businessman but others see you as a rude and pompous ass, which is the "true" you? How you view yourself, how others view you, some amalgamation of all views or each view is a separate but equally valid "you"?