Fernando Alonso has made an impassioned plea for people to believe he is leaving Formula 1 because he feels he has nothing else to achieve.
"I stop because I want to, not because I am being forced to," Alonso said.
"I want to stop because I achieved in F1 more than I dreamed of and it's time to achieve bigger things outside F1."
Alonso, 37, was responding to the suggestion F1 bosses should think about what it says about the sport that he was unable to find a competitive car.
Fellow Spaniard Carlos Sainz, who will replace his friend Alonso at McLaren next season, told reporters: "The fact that he's leaving is a big loss for Formula 1. To not have one of the best drivers, or the best driver, in motorsport at the moment on the grid is a big loss.
"It is something for Formula 1 and for everyone to consider - why one of the best drivers is leaving and why we cannot have a bit more competitive grid, where many drivers can fight for wins or for podiums."
Red Bull's Max Verstappen added: "Fernando is a winner and he wants to win races. He didn't see that happening in the near future and, of course, he has already tried for a few years so I can understand why he's leaving.
"There's probably some new adventures for him, probably he can win again. I think that would motivate him very much and we'll see what happens in the future, if he comes back or not."
However, two-time world champion Alonso, who announced his F1 retirement plans in August, expressed his frustration that people were not properly reflecting his reasons for leaving F1.
"In F1, there is always the feeling of here is the biggest thing in the world and if someone goes, people don't understand that maybe he wants to go," he said.
"They think he has to go because there is not a competitive car to race with. I could have a competitive car or maybe McLaren next year is super-competitive - who knows?
"But I don't want even to try. I want to stop next year because I think I can be a better driver, a more complete driver, and it would be better for my career outside F1 because this chapter is already done with a lot of success, in my opinion, and maybe there are other things outside F1 that I need to conquer. I didn't succeed in other areas of motorsport and I will try those.
"I could have a competitive car. I am not stopping because I don't have a competitive car.
"I have been saying the same since August. I stop because I did everything I wanted in F1. I arrived in F1, I won grands prix, I won championships, I broke records, I drove for McLaren, for Renault, for Ferrari, I am 37 years old and I cannot do more in F1."
Triple crown target
Alonso, regarded by many as one of the best drivers in the world, is hoping he can win the Indianapolis 500 next year in IndyCar.
If he can secure a drive and achieve it, that would make him only the second man in history after Graham Hill to achieve the so-called 'triple crown' of motorsport, of winning the Indy 500, Le Mans and Monaco Grand Prix.
He added that he was leaving F1 with happiness, not regret, and used the example of the Mexican Grand Prix organisers giving out Alonso face masks to the crowd for the weekend as an example of the standing in which he is held.
"I always felt a lot of respect in all my career in F1," Alonso said. "I have always been considered by the team owners, the team principals. I have always been respected and highly rated.
"So I feel very privileged to have raced for those teams, to have the respect of my team-mates, other drivers and you guys, the media.
"It has been perfect. It is the perfect time to stop and I feel perfect now.
"So tomorrow or next week, it is a sad thing I am leaving when I had the respect of all the team principals, the teams. I raced for the best manufacturers, I have been paid a lot more than when I was in go-karts, thinking about my salary in the future. I have a wonderful life, I arrived in Mexico and they give 30,000 faces for the grandstand to say goodbye.
"In Abu Dhabi it will be the same. I feel so privileged, so happy, so respected around the world, so I can only say thank you, and it has been a perfect journey, not a sad journey or a sad end.
"But I know it doesn't matter what I say because it is what the general opinion wants to think or wants to see."
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How to follow on BBC Sport
BBC Sport has live coverage of all the season's races on BBC Radio 5 live and BBC Radio 5 live sports extra, plus live online commentary on the BBC Sport website and mobile app - including audience interaction, expert analysis, debate, voting, features, interviews and video content.
Times BST until Sunday, 28 October when GMT begins. Broadcast times are subject to change at short notice.
|Mexican Grand Prix coverage details|
|Date||Session||Time||Radio coverage||Online text commentary|
|Thursday, 25 October||Preview||20:00-20:30||BBC Radio 5 live|
|Friday, 26 October||First practice||15:55-17:35||BBC Radio 5 live sports extra||From 15:30|
|Second practice||19:55-21:05||BBC Radio 5 live sports extra||From 19:30|
|Saturday, 27 October||Final practice||16:30-17:05||BBC Radio 5 live sports extra||From 16:30 (continuous)|
|Qualifying||18:55-20:05||BBC Radio 5 live sports extra|
|Sunday, 28 October||Race||18:30-21:00 (GMT)||BBC Radio 5 live||From 17:00|
|Monday, 29 October||Review||04:30-05:00||BBC Radio 5 live|