I wrote earlier about how wearing a mask that is not your true self may not be a good thing. However, in some cases, if you are looking to improve, especially in an aspect that is challenging (such as self-confidence, letting go of emotional pain), wearing the mask you wish to become can accelerate your progress. In short, fake it till you make it. Amy Cuddy puts it across well in this TED talk, where she uses body language as an example.
Dedicated to my friend Ag