Well, I've come up with my diagnosis, And I believe that you are infected. Yes, indeed, it's a parasite, in fact, But don't you worry. It can be dealt with. Unfortunately, it cannot be cured.
Do you perhaps remember feeling That you could do anything as a child? Do you remember internalizing The confidence and power that youth brought? Do recall those sensations?
I can predict the rest. Someone stopped you, Told you to think realistically. Put you down, causing you to doubt yourself. Doubt. That is what you are infected with. And as of then, it has been part of you.
I was inspired to write this after listening to my friend's nervous remarks about his performance in a musical.