Elon Musk had to quit this common bad habit before he became successful

As Tesla founder Elon Musk pushes to deliver the Model 3 cars to buyers, he's taken to pulling all-nighters and sleeping on the company floor.

Though the serial entrepreneur has experience working long hours and under pressure, Musk admits that he had to overcome one bad habit on the road to success: drinking large amounts of caffeinated beverages.

"There were probably times when I had like eight [diet cokes] a day or something ridiculous," Musk told the German automobile magazine Auto Bild in 2014. "I think these days it's probably one or two, so it's not too crazy."