Should you worry if you are not successful by thirty?

Facebook founder Mark Zuckerberg has just turned 30, joining the list of Mozart, Elvis, Madonna and Einstein who all reached great success in their twenties.

So should you worry if you have not achieved your dreams by the time you hit thirty?

Poppy Dinsey, 27, who set up outfit sharing site "What I Wore Today" at 22, told BBC Radio 5 live's Breakfast, that it was important to be "someone who works hard from the very beginning."

However Mark Warburton, who gave up his City job aged 39 to become a football manager, said there was "always risk attached" to following dreams but it had paid off for him.