Once again: How much brain do you need?

Regular readers of this space will know that I've been running comments from Dr. Mike Egnor, who - like Dr. Jeff Schwartz - has said kind things about The Spiritual Brain, on the subject of how people who have very little brain often manage to cope quite well:

I have many patients with surprisingly little brain tissue who are quite normal or even bright people. Conversely, I have many patients who are quite disabled who have brains that look pretty normal on MRI scans.
One of the best examples of excellent neurological function with diminished brain volume is a little girl who I've been caring for since birth. She is one of identical twins, and she was born with a huge fluid cavity that has replaced at least a third of her brain. I had the option to drain the fluid surgically, which might have helped her brain function. Yet since birth, she has been normal neurologically, and we have an excellent control- her twin sister (with a structurally normal brain). I've never drained the fluid because I couldn't find any evidence that she was impaired.
The little girl with the 2/3 brain is 6 years old now, and she is exceptionally bright, excelling in school, and cognitively doing better than her sister. She isn't quite as coordinated as her sister, but her motor function is well within the range of normal for her age.
I've cared for hundreds of patients with significantly diminished brain mass who are normal. In fact, it is well established that brain weight has no correlation with intelligence over quite a broad range- from about 1200 grams to about 1700 hundred grams (normal is about 1500 grams for an adult).

That's really encouraging for small people like me and people with impaired brain function. Don't let life get you down.