I don't believe in the board persona thing. I believe in substances... such as alcohol and marijuana... others I don't like, but they have a similar effect... you are what you're or you use something to lift you up to what you're ... and if those people are shy to be themselves (which I believe is the selves they like better), then theey just need their "doze"...
we don't use them substances for nothing (unless we're 13 and trying out new stuff)
However I do believe that there're people who're affraid to be themself when not being under the influence