have you ever had a concussion.i have had 4 the worst time i had bleeding in my brain broken rib and wrists and i was fully concious the whole time i was in the ER for four days.got put on one if thoose beepy things got a CT and had to have pain killers and a medication to make me stop vomiting.
Maybe I read your post completely the wrong way (impossible to judge tone over the internet), but it almost sounds like you are bragging about it. I hope I read it wrong.
As others have pointed out, concussions are a serious matter and cumulatively affect your brain function.
I myself have had one concussion. I was riding a 3-yr-old I was training, working on loping circles. The best I can remember (as I was knocked out), she tripped over her own feet and completely rolled over me. There was dirt on the saddle horn and the back of the saddle, and my right arm and leg leg hurt (consistent with her falling on her right side and rolling over). I don't remember getting up and I don't know how long I laid there. I had already walked 1/4 mile toward home before I remember anything (was over 1/2 mile from home total). It took me a good 30 minutes to "come back to the world". My mom was the only one home and she consulted with my uncle, who is a medical doctor. I was feeling fine after that and she was instructed to wake me up every 2 hours during the night to ask me a question (What's your name ... etc). But the next morning, I could not stand for more than 30 seconds without being nauseated and dizzy. We went to the ER and they ran all the brain scans. I was very lucky that there was no physical damage and it was just a grade 3 concussion, and not a more serious brain contusion. And I was wearing my helmet during the incident.
I have not had another head incident like that since, but I always have my helmet on when even handling my horses from the ground, and I'm very careful to keep my head away from legs when working under the horse for leg wraps, washing white socks, etc.
In your case with 4 concussions, I would be extremely careful. I would even consult with your doctor about any Alzheimers-delaying medications that may be beneficial for you when you are older, to potentially help prevent brain disorders such as those.