The Nets, who are unbeaten at home in 14 games, beat the Houston Rockets 105-96 last night to clinch their first playoff berth in 11 years.
Johnson, who scored 32 points during the victory, told reporters: "Honestly, I couldn't even see it. I kept saying to myself eventually this is going to turn around, things are going to turn for us.
"Eventually it did starting the New Year. We were a different team, our mindset was different and the way we played was different."
The Nets face the New York Knicks at Madison Square Garden later today.