Felipe Massa says Ferrari cannot afford to throw away any more points like they did at the Hungarian Grand Prix.
The Brazilian was putting on one of his best performances in Formula One when, three laps from the end, he suffered an engine failure that robbed him of a sure victory at Hungaroring.
A frustrated Massa admitted he found his retirement hard to believe.
"I don't want to forget the Hungarian GP, because in a certain way it was one of the best races I ever had in Formula One, but it didn't end as the others, with a win," said Massa.
"It was a shame, because I really think that me and the team deserved the success: we had a perfect race at a very important moment of the championship. Unfortunately we couldn't bring home the ten points we already had in our hands: it was really frustrating, but these things sometimes happen in motor sports.
"When the engine failed I had a strange feeling. It was like a nightmare and I wanted to wake up, but I couldn't, because I was already awake. It was an incredible disappointment. This sport can be really cruel."
Despite his retirement, Massa is still in the championship fight, eight points behind McLaren's Lewis Hamilton.
The Brazilian says he is staying cool about his chances, but he reckons Ferrari cannot afford any more mistakes.
"Looking at the standings at least I can stay calm, because not even Lewis won, but we can't throw away points like that," he said. "We lost ten, but the positive aspect is, that we've demonstrated that we're strong.
"The team has done some great work over the whole weekend, in terms of strategy and eliminating the problems we had in England and Germany.
"We've worked hard to make the car competitive again and this is a good thing for the upcoming races. But we've got to resolve the remaining problems: we have to be as competitive as at Budapest, but we need to raise our reliability. We can't repeat certain mistakes: we don't have any more excuses."