The Cleveland Browns crawled into Heinz Field Sunday. The Browns were without their star running back Trent Richardson.They were without their starting quarterback and their second-string quarterback. And their coach was coaching his last game on the Browns' sideline. The Pittsburgh Steelers came into the game having squandered their playoff hopes last week. They were without wide receiver Mike Wallace and tight end Heath Miller. They were also fighting to keep their season above a losing record.This was a game with nothing to prove. It was a game of the walking wounded. And yet there were lessons to be learned.