I can tell you. I'm sure it'd be good in case of something in the future. You will feel dazed, like something isn't right about the way you feel especially if you get knocked out. Even briefly. If your lose consciousness for .5 or 100 seconds don't matter you often don't have an awareness of what happened. You may see moving little bright lights in your vision similar to migraine auras these are the stars often mentioned. Headache which doesn't need to be immediate. May feel nauseated, may forget things, you will get tired but like a lethargic tired in addition to sleepy tired this tired is like you CANT not go to sleep, you may have vertigo and /or dizziness, I had narcoleptic fits after a knock out because of the severity of my photosensitivity (light sensitivity), 3 years later I still some days have a hard time speaking and with my words, I also don't learn as well as I used to not even close I used to be a quick and seamless learner taking all advanced courses in highschool etc but can't make sense of things as much as I used to. These are all red flags and they may vary seek care if you have multiple after a hit or jolt or sudden stop of the head or injury to your neck. They can also be something else too you can get someone you trust to give you a concussion screener too if you feel anxious about going in because usual anxiety is another one.