The Undertaker documentary series, "The Last Ride," is showing a side of The Deadman most fans have never seen.

A staunch keeper of kayfabe, Mark Calaway has generally kept quiet about his life outside of his character. WWE's documentary series chronicles the final days of The Undertaker's storied in ring career and gives fans a behind the scenes look at the man behind the iconic character.

The Undertaker appeared on Busted Open Radio to discuss the documentary series and his career. He said letting the cameras film him backstage and opening up about life outside of The Undertaker character was a rough adjustment.

"When we first started doing this, the camera crews would be there backstage and I would turn around and I would see them and would snap like, 'What the hell are you guys doing? Why are you filming me?' and then it would dawn on me, 'Oh yeah, I told you guys too,'" The Undertaker said. "It took me a little bit to get used to and honestly, it did not come natural to me, because I have tried my hardest to protect kayfabe and all those things. Honestly, this was in the last couple years. I mean, I would cringe when I would hear people, like we're doing now, talking openly about behind the scenes stuff. I would grit my teeth. I just really enjoyed that era. The bond that we all had, there's still a bond there, it just doesn't seem to run as deep as it used to. The honor among thieves mentality.

"I think I was the real last hold out to kayfabe and it's funny. I was probably the last guy to social media too. I remember I posted something, I don't even remember what it was. I normally don't do this, I don't normally look at comments, but I was kind of scrolling through and there was a comment that said, 'My childhood is dead. The Undertaker is now on social media. It's all over.' I'm thinking to myself, 'You're right, I'm sorry man!' That's my instincts, and it took a while to work through that."

The Undertaker's apprehension to breaking kayfabe didn't subside even as the wrestling industry changed its collective thinking on the matter. Even during filming, The Undertaker was unsure of what to do with the footage, and a documentary was not the original plan. He said he thought facing Roman Reigns at WrestleMania 33 would be his last match, so he wanted the footage because there wouldn't be another opportunity to get it.

"I was blessed far beyond what my imagination could ever even dream up when I decided to get into this journey into professional wrestling," he said. "It's kind of strange how (The Last Ride) came about and this process. We didn't start with the process of, 'Let's make a documentary.' This original concept just started, because when I got to Orlando and was going to work with Roman, in my mind that was going to be it. So I just wanted (the footage), because I protected this character for so long, and obviously the boys on the inside they got to see those kind of parts of me but the rest of the world didn't, and I didn't know what we were going to do with the footage but I knew that I wanted it and I knew I wasn't going to have another opportunity to get it.

"So that's kind of how it started, then next thing you know we're three years down the road and we have tons of footage. We realize like, 'Wow, we've got a really, really good story here about me coming to grips with my wrestling mortality.' Obviously I'm really proud of how this is turning out. In the beginning, I'd go back and forth. I would be, 'Well this is a horrible idea. My real fan base, they're not going to like it,' Then there's the part that's like, 'Okay, people have been clamoring for this for years and they wanted to see this.' So I've had all these dueling battles on whether it was a good idea or not, but I'm glad that I've worked long and hard with Dan Pucherelli, who produced it. (I'm) really, really happy it turned out the way it has."

The first three episodes of the series are available to stream on the WWE Network. The next episode will be available to stream Sunday, June 14. You can see a clip of The Undertaker's interview on Busted Open Radio below.