Let me elaborate on my struggles - I was bedridden in a dark room for 4 years barely able to open my eyes, and only able to read for 5 minutes per day. The impact forces from the hitting my head were not enough to cause those severe symptoms, which means it was most likely the cumulative effect of too many concussions. (I wrote about it here: DrewDigital - How Overdoing It Turned Me Into A Vegetable | A Post-Concussion Syndrome Story )

My case may be extreme, but when you are trying to understand a complex problem, it helps to examine extremes.

This study indicates that children are actually more susceptible to concussions than adults: Development of a Concussion Risk Function for a Youth Population Using Head Linear and Rotational Acceleration - PubMed

And this study found that childhood TBIs increased the chances of low educational attainment, a need for psychiatric care, the likelihood of receiving welfare and disability benefits, and early death. Not unexpectedly, more severe brain injuries and repeated brain injuries made these outcomes even more likely. Will My Child Experience Long-Term Consequences from a Concussion or other Brain Injury? - Elizabeth Sandel, M.D.