"Yes, it's terrible," the Swiss said, when after being retained as Red Bull's official reserve driver for 2013 was asked if sitting on the sidelines is difficult.
"Real torture!" Buemi, 24, said as he recalled last year, the first season after being dropped by Red Bull's junior team Toro Rosso.
He had hoped to return to the grid in 2013, but instead has signed on for the Red Bull reserve role yet again.
"Given the circumstances, it is the best option," said Buemi.
"I didn't have the opportunity to sign with a competitive team, so I decided to stay with the (Red Bull) team, who have just won the titles again.
"Working with Red Bull Racing is only a plus for my career."
But he admitted that Sundays at the scores of grands prix around the globe are far from fun.
"Definitely, for a driver there's nothing worse than not being on the track," he is quoted by Russia's f1news.ru website.
Buemi, however, said some recompense is his continuing race programme with Toyota. Last year, Buemi's hybrid prototype was running third in the fabled Le Mans 24 hours when teammate Anthony Davidson crashed heavily.
"Yes, I have signed a contract with Toyota and will be at the start at Le Mans and at least three other races," he said. "I also have 15 days of testing so it's a good programme.
"Also at the grands prix I won't just be a spectator, I will again work as an expert on TV."
Buemi said he will try again to make his F1 race return for 2014.
"Nothing can be ruled out," he insisted. "The situation in formula one is changing rapidly.
"But even if at the end of the year Mark Webber finishes his career, it is clear that there will be a lot of applicants for his place."