He told BBC Radio Cambridgeshire: "You've just got to keep winning and I think the team are happier with that win than any other this season."
Peterborough are now just two points off the automatic promotion places.
And Darren Ferguson's side, who have not conceded a goal in three games, have now taken 16 points from their last six matches.
"We've got the same mentality now as we had the last time we were in League One and we've just got to go into every game thinking that we're going to win," added Lee.
"We're scrapping now and while the last three performances haven't been great we've scored goals and looked strong as a team."
Lee struggled for opportunities under former boss Gary Johnson, but has been a ever present in the side since the return of Ferguson.
The former Tottenham spent time on loan with Gillingham, making four appearances and scoring one goal.
"Gary Johnson thought it was best for the team that I didn't play and you get periods like that as a player and you just have to keep working hard," he said.
"I went on loan to Gillingham and that was a great experience and then Darren Ferguson came back, I got back in the team and I'm just trying to make the most of my opportunity."
Source: BBC Sport
Source: BBC Sport