[alegsghed]

Or, is it the case that it requires a mind to comprehend a mind, that using an internal concept of mind is required to understand mind, that it is somewhat a generator of concepts of itself?

A mind is the only thing that can comprehend anything. But there are minds, human ones at that, that supposedly lack theory of mind, so having a mind would seem a necessary but not sufficient condition for forming a concept of mind.

Not far back it was thought a small percentage of genes was useful and the rest were junk, then understanding of transcription, methylation, epigenetics etc came along and somewhat changed that picture.

What's the chances something similar will happen re the brain?

A large degree of that junk DNA is still considered to be just junk. Popular misconceptions about using on 10% of our brains notwithstanding, nobody has claimed any part of the brain is junk. Well not since Descartes and the pineal gland.