The creative director behind the opening ceremony for the 2012 Olympics believes hard financial times have made it difficult for the spirit of the Games to last.
Danny Boyle, who was praised for his work in masterminding London's £27 million Olympic opening ceremony, said he felt the positive impact of the Games before they started and after they ended.
But he said the public will return to their "private battles", adding that it is "naive" to hope the optimism of the Games will continue.
The Oscar-winning movie director told The Sun: "I think it would be naive to say it could last.
"It's nice to have a fillip like that to feel good together, then you get back to your private battles.
"Obviously we are in tough economic times which means it is difficult finding jobs for people."
He added: "I got encouragement from the volunteers, and their idealistic belief, which was beautiful."
Boyle recently turned down a knighthood for his Olympic contribution, explaining he did not feel right accepting an individual award as the ceremony's artistic director when a cast of thousands, including the Queen being parachuted out of a helicopter, helped create it.