The Bees captain spoke to iFollow after the full-time whistle blew on Leeds United's narrow 1-0 victory, giving us his thoughts on the match.
"I think we are obviously disappointed to come here and lose the game," said John. "We came here on the back of two good results, and were looking to make it a perfect week. It just wasn't to be so we'll have to dust ourselves down and get ready for next week and another big game."
The 25-year-old also described his frustration with the end result following what he thought was a dominant opening performance.
"I think in the first half, especially after the first three or four minutes, we started to dominate," said John. "We were very good for about half an hour I suppose, then the goal comes. You come here and want decisions to go for you, and from our point of view it was offside.
"You need decisions like that to go your way but it didn't and we were trying to get back into the game from that point. Second half I think we huffed and puffed but it just wasn't to be in the end. So we are very disappointed to lose the game."
The Irish defender pointed out some of the differences he saw between the two sides, as well as quashing any idea that the atmosphere at Elland Road effected the result.
"What matters is what goes on between the white lines," he said. "As I said, first half we dominated and then huffed and puffed in the second half a bit more to force some things. There's probably credit due to them, the goal gave them a lift and it was a competitive Championship game.
"We have to learn from the positives, learn from the negatives and drive on."
The Bees are in action against Cardiff City at Griffin Park next Saturday, a game that John is expecting to be a physical test but one that Brentford can deal with.
"We dominated the ball again," said John. "For most of the first half we looked sharp as if we had picked up from where we left off. We just have to keep the energy and keep the drive and focus going.
"There's 12 games left and we're going to have to give it our all if we want it to be a successful season. I've no doubt that the boys in there will give everything for the last 12 games of the season.
"We've our own style, our own philosophy, and it doesn't matter hwo we play against. We play our way and we believe in what we do. We're good at what we do and we'll keep doing it."