Saturday's big win over Edinburgh confirmed Glasgow's place at the top of Conference A and secured a home semi-final against either Ulster or Connacht.
"I think the way we've playing and the mood around the camp this last few weeks just showed on the park," he said. "We've been building to this and it was a really good win. We had to be up for it. We'd been embarrassed by Edinburgh and they'd been playing some really good rugby around Christmas time. They ended up winning the 1872 Cup which was a goal of ours, but we're in good shape heading into the play-offs.
"I always go back to that quarter-final against Saracens. We were embarrassed that day by them. It showed what we needed to do and where we need to be to try to play the semi-final here," said Johnson. "We're all enjoying coming to work. This time of year especially you can all be getting a bit annoyed with each other but everyone is really enjoying each other's company this year and we're trying to make the most it.
"Last year we were embarrassed again (in the semi-final loss to Scarlets). In bigger games we didn't come to the mark so we're having to go again. We're in Glasgow the rest of the way now."