Great thread, Anne, and it strikes a tremendous chord in me!
One Friday morning in August 2005 my wife and I left for an overnight together. I was a "normal" male as far as I knew. 24 hours later I was, for the first time, dressed in stockings, heels, and garter, and my wife and I had been looking on the internet for a dress for the person we soon named "Tina". It was at that point that I was faced with the fact that I did NOT know myself, and had not for 55 years. It was a bit of a shock, but that shock also propelled us to "fix it"! How to fix it....get to know Tina, who she is, who she has been, and who she might be.
There have been many threads asking, "why do you dress". I have no idea what the answer might be 10 years from now, but right now I need to "make a life for Tina" (my bi-line here) in order to "know myselves"! In our opinion, the only way to know about Tina is to BE Tina.
So, the direct answer is: I know myself better because Tina exists, and I know myself better every day because Tina exists.