Over the course of a 17-game regular season, every NFL team is likely to have their highs and lows. The same could be said for individual players, specifically the quarterback position. One game, you could be facing one of the worst defenses in the league and throw for 300 yards and three TDs whereas the next week you could be facing a top five defense and throw for under 200 yards and toss a couple of interceptions.
The goal of a franchise quarterback is to be consistent on a game-to-game basis, regardless of the opponent. Take care of the football.