Sharing your good luck isn't selfless, it's actually the most selfish thing you can do, says author and risk expert Barnaby Marsh. Why? Because it's highly likely that an opportunity you pass on to someone else will come back to benefit you down the track. Luck really is a social force. "There’s a saying we have, that, 'You don’t get lucky by sitting home watching TV.' You get lucky by being out there, by talking with people, by interacting with them and engaging with them, letting them know what excites you and letting them know how your talents might be able to help them," says Marsh. Some social butterflies will pass off their good fortune as being in the right place at the right time, but Marsh explains that it's a case of purposeful positioning and there is often much more preparation behind the scenes than you'd think. Marsh also explains that there are two parts to luck: the event and the outcome—and poor management of the former is where luck turns sour. So why are some people so much luckier than others? It's not that fortune favors them, it's the way they position themselves to play the game. Barnaby Marsh is the author of How Luck Happens: Using the Science of Luck to Transform Work, Love, and Life.