Paul Trollope's side have raised eyebrows with their impressive start to the League One campaign but were brought back down to earth with a 5-1 defeat at Carrow Road on Saturday.
And Lines saw the defeat as a reminder that they can ill afford to let their standards slip if they are to mount a promotion bid.
He told the club's official website: "Obviously we did take a bit hammering at Norwich.
"But I think maybe that may have not been a bad thing, because it stops people from getting carried away and will get the lads back on a level playing field.
"We know that we need to be on top form every game if we want to be in around third place."