After 23 years at Blizzard, we were all a little surprised to hear that Chris Metzen had actually retired.

Metzen: I'm actually a very different guy to that guy.

He'd helped guide the development of every major franchise at the company and thanks to his infectious enthusiasm on Blizzcon's stage each year, to many fans, he was the public face of Blizzard Entertainment.

And yet just two months ago, at the age of 42, he announced his retirement, not just from Blizzard but from the wider world of video games. What had happened?

In a very personal interview with excellent podcast man Scott Johnson, Metzen has now spoken about the reasons leading to this decision.

"Leaving Blizzard was an incredibly difficult thing," explains Metzen on a special episode of The Instance podcast. "I'd been there since, essentially, I was a kid. I think I was 19 when I got hired and it was my whole life, it was my identity. And it was in many ways, all-consuming.

"It was just incredible, but there can be a cost sometimes to running that hard."

Despite the huge success that Overwatch has seen this year, the story behind that game's development is anything but straightforward. Previously known as Project Titan, Blizzard had spent significant time and resources trying to create the world's next big MMO, but eventually cancelled the project after a whopping seven years in development.

"I think during those years I burned out really hard," explained Metzen. "I think in my heart, I needed a change in my life. I wanted to slow down, I wanted to just not carry the weight of it all.

"But when you've been at a company like Blizzard for as long as I have, I think about Shawshank Redemption: I'm an institutional man now. I'm a Blizzard guy, through and through. I love that place. I love the people.

"It made me feel schizophrenic."

Metzen, along with the Overwatch team, had eventually managed the impossible and turned this failed project into yet another huge Blizzard hit. But by then, the damage was done.

"I started having panic attacks left and right and just non-stop anxiety," said Metzen. "Before I finally retired, I think I had been having panic attacks all the time, but I didn't know what they were. Kat and I would go on dates to go to a movie and almost all the time, I would start panicking in the middle of a movie. I had no idea what was going on."

Eventually these panic attacks would be diagnosed for what they were and with the arrival of a newly born daughter, Metzen was forced to make what must have been an excruciatingly difficult choice.

If you're a Blizzard fan you'll want to listen to this podcast, because this man has played such an important role in the games you love to play. But even if you're not, it's an incredibly worthwhile story.

It turns out this video games rockstar of a man, all smiles and charisma on stage, is a human being just like the rest of us.