This is a myth. This is outdated information that may even slow the recovery process. Rest helps the brain recover from a concussion. However, it’s reasonable to check on the concussed person while they sleep to make sure their breathing pattern hasn’t changed or to briefly wake them up to make sure their symptoms are not getting worse. The concussed person should be immediately seen by doctors if they fall asleep shortly after receiving a concussion or can’t be woken up.