Johnson said if he was happy with the performance put on by his side in beating Georgia 41-10 at Otago Stadium he would be going home early.
The former King Country colt admitted he was annoyed with England's effort.
"We were again way behind in the penalty count early on, and you can't do that. We got ourselves out of that and went ahead. But we just turned the ball over too much," Johnson said.
"We are under no illusions. We need to get a lot better for next week and going forward."
The Georgians dominated for long periods of the game and it was a rather flattering win for England.
The English had little ball to play with in the first half and were on the wrong end of referee Jonathan Kaplan's whistle for much of the game.
Johnson said his side needed to be a bit sharper, and get used to playing at this level.
"We need to understand what test match rugby is about. We need to hold on to the ball and not force passes.
"We were sloppy at times. It is a simple game and we made it difficult for ourselves. We don't want to be the type of team that is happy with those standards. If we are then we will go home early."
If Georgian goalkicker Merab Kvirikashvili had his radar working - he missed five penalty shots in the first hour - it could have been quite a contest with half an hour to go.
But England slowly got on top and when big centre Manu Tuilagi steamed in under the bar, England was home and hosed.
Loose forward James Haskell, who was called into the side only an hour before kick-off as Nick Easter cried off with a back injury, said the high penalty count was not good enough.
"At one point I think it was an 8-1 penalty count, and that is just not acceptable. If we are not getting it right then we just have to change the tactics and get out of it," Haskell said.
"There is a lot of talent and potential in the side which is not coming out on the table at the moment ... we have to realise what is required to play the sort of rugby for these pool games."
Haskell was one of the most impressive for the winners, while captain Lewis Moody made an encouraging return from injury.
Tuilagi ran hard and scored a nice try, while his midfield partner, Shontayne Hape, looked good in most things, scoring twice.
They were Hape's first points for England, and he said afterwards the side had to learn how to bury teams in the second half.
"It was good to get early chances and get over the whitewash ... second half we gave away too much silly ball. The gaffer at fulltime was not that pleased," Hape said.
"Obviously pleased to get the win . . . but we can't do that to other teams or they will bury us."
Kaplan sent hooker Dylan Hartley for a spell on the sideline as the English infringed right on the break.
The Georgians took the resulting scrum and impressive No 8 Dimitri Basilaia charged over to score their first try of the tournament.
Basilaia played well, as did bruising openside flanker Mamuka Gorgodze.
THE SCORES:-
England v Georgia
• England 41
Chris Ashton 2, Shontayne Hape 2, Delon Armitage, Manu Tuilagi tries, Toby Flood 4 con, pen
• Georgia 10
Dimitri Basilaia try, Merab Kvirikashvili pen, con
• Halftime: 17-10
• Crowd: 20,117