Mason, 32, leaves co-founder Eric Lefkofsky and vice chairman Ted Leonsis to steer Groupon (GRPN), find the next chief executive, and get the company on track. Mason will likely be remembered as a brilliant, arrogant, eccentric, anti-authoritarian (or at least anti-normatively polite) startup whiz kid. Thanks to Steve Jobs and the Jesse Eisenberg version of Mark Zuckerberg, this puts him in good tech-startup-fantasy company. Lefkofsky, Leonsis, and the incoming CEO will have the tough job of making Groupon successful.

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A sort of positive glow is already being built around Mason’s legacy. Forbes, for example, claims that Mason “did what great founders do: He innovated and he built.” (And he pushed the envelope on GAAP accounting!) Mason was incredibly likable in his I Was Canned letter. You sort of want to give the guy a hagiography-lite to get him through the next few months in the wilderness.

But what I really like about Mason’s departure is that he accepted with grace and humor the fact that his company had outgrown him. He was good at coming up with a new idea for a business. But he was bad at growing and managing that business, fending off competitors, and adapting to a fast changing landscape.

Haven’t we seen this before with other founders? Sometimes the person who has the genius idea can take a company only so far. Sometimes it takes a different manager with a broader vision to make a startup a permanent, thriving, growing, changing, innovating part of the corporate landscape. I hope the idea that it’s okay for founders to leave becomes part of Mason’s Groupon legend. And given that Mason was fired and didn’t decide on his own that Groupon needed a new leader, his departure also shows why it’s so important for companies to have strong boards that aren’t just there to push the founder’s agenda.

Andrew, we’ll miss you terribly, too. That is, until you come back.

They always come back.