Look at yourself into a mirror. Stare at it.Can you see a mask staring back and who is really behind it? For some, we have this ability to be poor judges of our own performance and often overate our abilities. This is also know as ' The Impostor Phenomenon '.
Sometimes, we have feelings of phoniness which appear to alter our goals unexpectedly, and often protects us against subconscious self-delusions.

" The motivation was to avoid doing poorly, looking weak"

Research has shown that many self-styled impostors are phoney phonies : They inherit self-deprecation as social strategy, consciously or not, they are secretly more confident than they let on. Furthermore, they are also able to lower others' expectations on them and thus get credit for being humble.

Another perspective to look at this impostorism is that, by acting as an impostor, it could help a person to lower it's expectation for a performance and concurrently taking off the pressure laid on him or her.

Lastly, it reflects a respect for the limits of one's abilities.