The 25-year-old former Leeds United man is relishing his opportunity to play in the Premier League and has been a key part of Chris Hughton's team's recent unbeaten run.
Johnson has struck up a good partnership with Norwegian enforcer Alex Tettey, who could be back in contention following a thigh problem against Wigan Athletic on Saturday.
However, he knows he cannot rest on his laurels, as he said: "I am playing my best football, am enjoying my football, and getting picked every week.
"But I know it can change in an instant, so I am not getting too complacent and not getting ahead of myself.
"I just want to get picked every Saturday and that comes down to training hard and being fit and available."
Johnson added: "I have learned a lot more from last season. It was my first year in the Premier League and this season I am more disciplined in the job I do.
"I am a holding midfielder and more of a defensive player, but I am learning every game I go into.
"This is a great league to be in and I want to be in here for as long as I can and learn more."
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