Well my symptoms which consisted of dizziness and a bit of a sore neck are now gone. The last time I was sure I suffered from a concussion is nearly a decade ago. Will the brain be more susceptible to a second concussion after having a first one? Regardless of time passed in-between say a decade? Will it be more vulnerable to injury for a lifetime? I thought we were build to be fairly resilient to fast head rotations due to the cerebrospinal fluid preventing collision with the inner skull. How fragile is the brain actually when it comes into contact with the skull? Does simply a light touch cause bruising on the brain or does it take a somewhat of a slam to cause injury?