>>Wear that helmet!

Back when I worked in a motorcycle shop, I'd tell customers they really only needed to wear a helmet when they were going to have an accident — but if they knew that, why not just stay off the bike for the day, sleep in?

More seriously, motorcycle helmets (the ones I know about) protect your brain by keeping the g-forces it experiences within limits. It does this by absorbing energy, and it does that by getting destroyed - although the damage might not be apparent. On top of that, the main absorption layer wears out over time, just from wearing the thing. So, you need a new one every few years.

Recently, I've been reading that the NRF2 pathway might be protective against TBI (seems to protect against follow-on damage like localized anoxia, ROS). You can increase that by eating isothiocyanates like sulforaphane (in many cruciform vegetables). Eat your broccoli!

Also, I've seen studies that indicate that TBI secondary damage is primarily mitochondrial, so I'd expect methylene blue to be helpful as there's evidence that it can undo neuronal mitochondrial damage (but WARNING I have seen nothing on MB and TBI - and biology doesn't work like chemistry of physics so I’m guessing here).