I think I've definitely been guilty of not being myself at the start of a relationship in the past, but only because I tried to be what I thought the guy wanted me to be.
Obviously that never worked out for me, so with my current boyfriend, I just decided to be completely myself and if he doesn't like who I am, he's not worth the hassle.
I am amazed and astounded to say that he actually likes the real me - who'da thought it eh?!
This exactly, I am who I am, if they don't want to be with that person, then no point in bothering