Sebastian Thrun, former Googler who helped invent the company’s driverless car and undoubtedly is now a millionaire many times over, said he recently took up as an Uber driver.

And then he was banned by Uber.

Thrun said he loves ride-hailing apps such as Uber and Lyft. And he was motivated to give them a try as a driver.

“I’m a big fan of this. I think we should be able to try jobs in a heartbeat,” Thrun said Thursday at a San Francisco conference called “Next: Economy” about the future of work.

He signed up and soon was giving rides in his Tesla. He pointed out that becoming a traditional taxi driver is hard – in cities such as New York it requires an expensive, special license called a medallion. The barriers to entry are really high. Not so with Uber or Lyft.

Thrun’s first two passengers gave him a top 5-star score.

“I was really proud,” he said.

But he soon discovered that he was effectively banned from the app as a driver. He still has no idea why. He inquired with Uber about his sudden banishment and said he never heard back.

Thrun, who today leads the online education company Udacity, said the experience didn’t discourage his belief in the usefulness of trying new jobs quickly and easily. He considers it to be a way to discover what you’re really good at, what talents you might have.

“I think the ability to take these jobs so quickly – and lose them – is really great,” he said.

Uber declined to comment.

Staff Writer Brian Fung contributed to this report