Perfect Enough?

I may be in the wrong profession.  At first glance, that initial statement doesn't make much sense - I like the science of medicine, I like the human aspect of medicine, I like the versatility of medicine.

But what I don't like is that ever-pervasive feeling of wanting/needing to be the Perfect Doctor.

How can one even comprehend this? Is it rationalizing feelings of always wanting to do better, always wanting to learn - or am I just too insecure to be in this field?  I nit-pick, I overanalyze.  I wake up early in the morning with these thoughts in my head...  I dream about it.

Am I just trying to better myself, or do I just not believe in myself?  And if the latter is the case - is it really me or is it just my thoughts?