A survey has revealed that most people regret not working harder at school and not saving enough money during their career.
Starting smoking, not exercising enough and not seeing more of the world are also in the top five biggest regrets revealed by Electric Zebra, the company that makes cigarette substitutes.
Three-quarters of the 2,000 people quizzed by the "electronic" cigarette firm also said that they did not believe it was possible to live a life without regrets, the Daily Express reported.
On average people in Britain spend 44 minutes every week thinking about things we should have done differently.
The survey found that the biggest area of regret is love lives (20 per cent), family (18 per cent), career (16 per cent), health and finance (both 14 per cent).
But two-thirds said their regrets led them to think more positively and they learnt from their mistakes.
Nearly half said regrets influenced the way they live.
"It's significant that 64 per cent of people list taking up smoking as one of their biggest regrets," said Dr Sarah Brewer, medical adviser to Electric Zebra.