I remember in an eight grade game coming back to the huddle and the lineman who played next to me was talking about his sister's homework. He clearly had a concussion and we (the players) sent him to the sideline where the coaches berated him for coming out of the game and sent him back (this was in the 80s).

Already at the JV level I saw multiple concussions in games. Not kos but guys woozy liked they'd been punched. Nobody cared back then (US south).