Both Marquez and Honda team-mate Dani Pedrosa remained out on slicks as a rain shower hit the last MotoGP round at Aragon, despite the rest of the field pitting to change to wet-shod bikes.
They ended up crashing and could only finish 13th and 14th respectively when they rejoined. It was Marquez's second straight fall in a race after an accident while chasing Valentino Rossi for the Misano lead a fortnight earlier.
"Now when you look at it on the TV, I was really stupid to continue with the slick tyres," said Marquez at Motegi ahead of this weekend's Japanese Grand Prix.
"But at that time I was thinking that way. It was completely my decision to stay out because I thought I was able to finish the race - only three laps remained.
"The grip was not so bad, but when the tyres cooled the grip was a disaster.
"The correct decision was what Jorge [Lorenzo] and Aleix [Espargaro] did. I now know for the future - I'm always getting more experience."
Prior to his recent errors, Marquez was on course to have his first opportunity to wrap up the 2014 crown at Aragon. He can do so at Motegi this weekend if he maintains or improves his current 75-point lead over Pedrosa.
But with three more races to come after Japan, Marquez said it does not matter to him if it takes longer to secure the championship.
"I'm happy because there are still four races," he said. "We will try to take this weekend like a normal race, try to push like always and try to be fastest and fight for top positions.
"It's nice to have the first chance [to clinch the title] here because it's Honda's home race, but I know it will be difficult because I need to finish in front of Dani and Valentino [Rossi], which means I need to fight for first or second, because Jorge will be there too.
"I'm not nervous, it will be nice for Honda to win here, but for me it's just important to win it.
"You know how my riding style and my mentality is - I always try to push."