In a bid to isolate the worthiest candidates, Facebook would ask this soul searching question: “On your very best day at work — the day you come home and think you have the best job in the world — what did you do that day?” It’s a tricky question for many to answer. But whether you’re a surgeon saving lives on the operating table or on the frontline at the customer service desk dealing with the usual tedious grievances; a ‘good day at the office’ probably ensued because these intrinsic ingredients energised you: