Jenson Button says he is baffled by his current lack of pace which resulted in yet another race to forget for the McLaren driver.
Having made a strong start to the Championship, which included a win at the Australian GP, Button has fallen off the pace in recent weeks.
The Brit has scored just two points in the last four grands prix with his Canadian GP ending with him down in 16th place having been lapped by his race-winning team-mate Lewis Hamilton.
"I just had no speed at all," Button lamented. "I couldn't look after the tyres, I had no pace. There was nothing there.
"It's been the same at the last couple of races. I don't know why it is. Normally it's something I'm pretty good at.
"I haven't got a clue what is going on. Every time we think we've some good ideas we don't seem to make any progress. I don't know why that is.
"I'm also driving around one and a half seconds slower than the leaders, one is my team-mate, and I don't know why because I can't push the car any quicker. I'm not that slower than them.
"So this was a terrible race, I've never had one like it, and they seem to get worse and worse,
"I'm pushing the car to its limits and yet I'm so far off the leaders. It's a little bit confusing.
"Every time you jump in the car you're confident and excited it's going to go well, and every time you make changes you think you are going to improve. But it's not happening.
"I'm confused and very lost. I don't really understand what is going on at the moment."
Button, known for his smooth driving style, denied that the problem was related to his Pirelli tyres.
"Definitely not, it's not a tyre issue," he said. "I can't be the only person that can't drive on these tyres. It's impossible.
"They're normally something I can work with and get the best out of more than most, but it's not the tyres.
"Looking at it I did three stops and most people did two or one, yet it's normally the other way round."