Successful entrepreneurs often attribute their success to their mentors, whose advice was vital – both when they first established their business and later, during the inevitable difficult times.

Recently, I met the successful entrepreneur Ajaz Ahmed. He told me that, as a teenager, he was so impressed by the office building of Ashton-Tate, a local software company, that he sent a stream of letters to the boss, Paul Sloane. Sloane sent him lateral thinking puzzles to test his determination and problem-solving ability, before later hiring him.