I don't think it actually matters whether you're any good at the impersonation - the point is to convince your brain that you're creating a new persona, rather

I don't think it actually matters whether you're any good at the impersonation - the point is to convince your brain that you're creating a new persona, rather than trying to change your existing one. (An overarching theme of TLP's writings is how extraordinarily good the brain is at insulating itself from change.)