Carrick brain center, Dr Carrick himself, and his disciples.
I learned a lot when my 8th grade son ended up in the pediatric ICU due to 2 concussions, 5 months apart, and the second one (playing football) was a glancing blow. He developed "Disautonomia" also known as POTS (positional orthopedic tachycardia), and missed a year of school.
Current state of the art treats the symptoms, These guys have figured out how to help treat the causes and rewire the damages. it looks like Voodoo, but it works. Connor is healthy, has no symptoms, and is racing due to them. It took 4 years for him to fully recover. I literally watched them take connor from a state where he could not stand, or speak due to an "attack", and in 15 minutes have him stable and coherent without medication of any kind. Recovery from a "bad" concussion can literally take years if it generates follow on issues.
They work on Pro athletes all the time, and Dr Carrick spent (and spends) a lot of time working with the Military on TBI recovery.
Over the past 8 years of Coaching Rugby, I have had kids get concussions, and several of them went to see the local Carrick guy, with excellent results. I have had parents get mad at me because I would not let little Johnny play without a proper recovery and return to contact period, and because I have sat kids who "got there bell rung".
Hell, I have played nothing but contact sports, and I ran around in an armored vehicle for 3 years, and until my son's issues, I never realized how lucky I had been, because I did everything wrong, and didn't pay the price.
av8tor is 100% correct on the helmets and the padding, and on the initial recovery. Don't watch TV, don't read, don't use a computer. Relax and heal. Everyone is different, but the basics apply all the time. It may be 3 days, it may be 10 days for the initial recovery. it will be multiple weeks if not months for "full" recovery.
it is scary stuff when you really look at it. And yes, some people concuss easily, some do not, and it changes over time. Medical science has not figured out why yet.
The number one cause of serious TBI/Effects from a concussion is sustaining a second one before the damage from the first heals. You can be mildly concussed, and even a minor hit can cause a cascade.
It is not something to take lightly, and it is why most youth sports now have a multi week "return to contact" protocol that starts after the initial recovery period.
Hans, Helmet and proper Roll bar padding are the holy trinity. Right side nets and head containment is also vital.
This is also why it is highly important to replace a helmet, or at least have it re lined after a hit. You compromise the cushioning effect even if you cannot see any damage with the naked eye.