Tesla has always been fairly open about its autonomous vehicle efforts, to the point where CEO Elon Musk is a bit too optimistic about the company's future progress.

But why is Tesla so pushy about Autopilot and autonomy? According to Elon Musk, it is because of an incident in which a Tesla driver fell asleep at the wheel and killed a cyclist.

This tidbit of information came after a story about a Tesla owner in Norway who was caught drunk and falling asleep at the wheel. Apparently Autopilot recognized that he was not paying attention to the road and brought the car to a complete stop.

According to Musk, the same kind of story is why the automaker pushed so hard to offer the first version of Autopilot to Tesla customers. In that case, a driver fell asleep at the wheel and caused an accident, killing a cyclist in the process.

It is not clear what caused the driver to fall asleep at the wheel, but the driver later filed a lawsuit claiming that the smell of his new car caused him to doze off. Unsurprisingly, the suit was not successful.

Autopilot was finally launched in October 2014 and has been steadily upgraded and improved over the years. While it is not yet fully driver autonomous, it is a tool designed to assist drivers and ideally make their journey easier and safer.

Of course, the system is not without criticism. Because it is not fully autonomous, the name "autopilot" has been criticized as misleading. Mask staunchly defends it because it is based on an aircraft autopilot system that is not fully autonomous.

Tesla has also faced criticism over safety concerns, most recently over the fact that the company uses drivers as unqualified safety testers rather than doing everything privately with qualified personnel. Tesla's Model 3 and Model Y also lost their IIHS safety ratings when they removed radar from their Autopilot system.

But if what Musk says is true, it shows that Tesla's heart is in the right place. While Autopilot has been involved in some high-profile accidents, there are always examples where the system has prevented some disaster, and the majority of us will never know it. That can only be a good thing.