Jorge Lorenzo has revealed that he briefly decided to retire from MotoGP in the wake of his string of violent crashes in 2008.
The Spaniard's impressive rookie year lost momentum in the middle of the season following a series of ferocious accidents.
He continued to race after breaking both ankles in a practice crash in China, but then had to skip his home race at Catalunya due to a head injury from another fall.
It was while recovering from this injury that Lorenzo was on the brink of quitting the sport.
"I had thought it was over for me," he told Motosprint.
"After the fourth bad crash, which occurred during practice at Barcelona, I almost broke my head. I took a heavy blow on the side, and for about two days I couldn't even remember who I was. I'm serious, I couldn't remember my name, nor what I was doing. It was a really heavy blow.
"When I realised again who I was and what was happening, I decided to quit racing.
"No, I said more than that. I said: 'if I carry on doing this, I'll end up killing myself sooner or later.'"
Lorenzo admitted that it was the first time in his career that he had been afraid.
"This is a sport where something really bad may happen, so you tend not to think about it," he said. "Clearly, when you do think about it, as a rider you're finished. Indeed, for at least a couple of days, I had considered myself finished."
He said it took some several races to restore his confidence from that low point, and that his opening lap crash at Laguna Seca a few months later set him back again.
"When I felt myself again and got back on the bike, this thought [of retirement] suddenly disappeared," Lorenzo explained. "Thankfully the human mind changes very rapidly sometimes. For sure, however, I promised myself I would change my approach to races.
"I remember that at Donington I was among the slowest in practice, but in the race I slowly started to make up ground and in the end I finished sixth. Then at Assen I was sixth again, while at Sachsenring I crashed but the track was wet because of the rain so that's acceptable.
"However, at Laguna Seca I ended up doing another highside: I was regaining confidence but lost it all again all of a sudden. So I had to start over once again.
"But I matured that season, I acquired the knowledge for the reasons why you go quick. And most of all, I also understood when it's better to slow down."
Although Lorenzo did not win again in 2008 following his crashes, he returned to the podium at Misano and held on to fourth place in the championship, before challenging Yamaha team-mate Valentino Rossi for the title this year.