Just to reiterate what Mark said that this is a bizarre claim by someone who sounds like they are trying to pretend they know more than they really do. The brain and how it is affected by PCS is way to complicated for anyone to come out with this sort of ludicrously precise figure about anything.

This time you know what you are doing, you've had all this before and you understand it. You won't make all the stupid mistakes that many of us make early on in our injuries. Use that knowledge, plus anything else you can learn off this forum, and you may well be able to recover much more than '25%', whatever that is supposed to mean.

The key I found to getting understanding from people were letters and reports from health professionals. Even though I didn't think much of most of the ones who saw me (or of the ones who've seen you, by the sounds of things) one positive is that your concussion specialist has stated that you have an injury to your brain with serious functional consequences. Get this in writing if you don't have it already, and make people read it who don't understand. That generally worked for me.

Good luck!