In my experience - no. I've had concussions spread out over my life since a pretty serious one at the age of 9. Each time it seems to take less of an impact to concuss me, and the symptoms are worse. I trace it all back to that original concussion 24 years ago, though I couldn't prove it and most doctors would probably think I was mad for saying so.

There is evidence that jockeys, footballers and others are more likely to be concussed if they have had previous concussions. The recent evidence regarding chronic traumatic encephalopathy also suggests long-term, unhealed damage from concussions.

Finally, functional MRI scans show that when someone who has had a concussion performs just as well as someone who hasn't on a mental task (as we often can) our brains are actually working a lot harder than theirs are, with more blood flow to greater areas of the brain in order to achieve the same result. Which means that someone who appears to have completely healed, may just have trained their brain to work harder and compensate better for the damage done by their concussion(s). But there will be a limit to how many impacts the brain can sustain and still effectively compensate in this way.

Overall, I loved various risky sports, but no way is it worth it for me any more.