Elon Musk. [Source: BBC]

Elon Musk has just become the richest person in the world, overtaking Amazon founder Jeff Bezos.

The Tesla and SpaceX entrepreneur’s net worth has crossed $185bn (£136bn) after an increase in the share price of the electric car company.

So, what is the secret of his success? A few years back I spent almost an hour discussing exactly this with him. To mark his new milestone we decided to dust the interview off and share it with you. So here is Elon Musk’s guide to success in business.