The one thing you should absolutely not do is engage in anything that can give you another concussion. A second concussion before recovering from the first can

The one thing you should absolutely not do is engage in anything that can give you another concussion. A second concussion before recovering from the first can kill you. So no, he was not anywhere close to the mark. https://en.wikipedia.org/wiki/Second-impact_syndrome https://en.wikipedia.org/wiki/Second-impact_syndrome