Dude, I thought I was a fake as my viva was so short... I thought I was a fake as I spent most of my 3 years down the pub or watching trashy TV chat shows and not doing any research...
I thought I was a fake for managing to get all my colleagues and supervisor to present the papers we co-authored as I didn't want to...
Meh, who cares? I mean, if you pass, you pass... you *could* be incredibly moral and brow-beat yourself and then find out that as you progress through the PhD you naturally get more confident and draw more on your own skills and knowledge.. or you could perhaps, accept that your supervisor knows what he / she is doing and therefore stop stressing so much