However, the former World Cup winner also knows his squad must improve dramatically in a number of areas if they are to challenge with the cream of world rugby.
Johnson has also singled out the fitness of his squad as an area he is keen to improve as his side progress.
Johnson said: "We have won consecutive games. Nobody is getting carried away with it.
"There are lots of improvements we can make with players fitness-wise. We can improve certainly if we want to compete with the best in the world.
"The guys are fit - but there's being fit to play in the Premiership and Six Nations and fit to try to beat the best teams in the world.
"That's what we need to get to. Some guys are there and some guys aren't because they didn't know what it takes. They have only come into international rugby this year.
"Now they do know what it's all about. They need to be realistic and set their targets higher. If you want to get better, you have to raise the bar."
England dropped to eighth in the world after losing away to Ireland but they responded in emphatic fashion with a 34-10 victory over France before sealing second place by regaining the Calcutta Cup from Scotland.
"You have to go through those ups and downs. We had to get better and we have started doing that," said Johnson.
"Quite a few guys have taken big steps this year. It bodes well for the future."
Delon Armitage is one of those players. He was voted England's player of the autumn and nominated as one of six players of the RBS 6 Nations.
"Delon has started every game for us. He came in and looked assured from the first training session he did," said Johnson.
"He's physically got what it takes and he seems to have it mentally as well. He's got better and better and not rested on his laurels at any stage."