Drury, 32, told BBC Radio Norfolk: "Perhaps we got a bit carried away at 3-1, thinking we've won the game.
"You do have to concentrate a bit more and obviously we have to make sure it does not happen too often."
The City full-back scored his first goal in more than five years when Wes Hoolahan played him in.
"It was a bit of a blur to be honest, Wes put me through with a great through ball," he said.
"Their keeper came out and I managed to get it past him, I don't really know what happened after that.
"You're thinking 'don't miss, the lads will give you stick'. Russell Martin scored the other week so the pressure was on to get among the goal scoring."
Norwich boss Paul Lambert stuck to his favoured diamond formation despite a 2-0 defeat by Hull on Saturday.
The system gives the full-backs more responsibility to the fill space in wide areas and former Peterborough man Drury says he relishes the role.
"The gaffer encourages you to get forward as much as you can," he added.
"Your first job is still to defend, but if you can get involved with the forward play you do it as much as you can."
Source: BBC Sport
Source: BBC Sport