Peter Isackson | A year ago, Elon Musk was officially worth about $20 Bn. Two weeks ago, he became the world’s second-richest person, with a fortune estimated at $128 Bn. Thus, Musk deserved a lengthy video interview with the Wall Street Journal. It could probe into how Musk managed to become the world’s wealthiest and most admired innovator. The Journal couldn’t saddle any random hack with that formidable task, and so its editor-in-chief, Matt Murray, rose to the occasion. The interview lasted half an hour and can be viewed on YouTube.