The first game of a season is always dangerous. True, this is at least a real game - a concrete piece of evidence indicating what kind of football season you’re likely to get.
But it’s so easy to overreact to that data. Maybe that team you beat is actually really bad. Maybe that team you lost to is actually a title contender. Maybe the better team lost because they haven’t figured out which players to play.
That all goes doubly for the first game under a new coach, when you want everything good that happens to be a reflection of his influence.