After just finishing his latest run, and just before he returns to Glasgow, he mulls over this fact.
"Seventeen festivals now," he muses. "It's been insane..."
The Irish funnyman burst on to the comedy scene in 1996, when he was 24, winning the So You Think You're Funny? talent show at his first Fringe.
Two years later, he appeared on Channel 4's new comedy showcase; Edinburgh or Bust, selling out every night and being nominated for a Perrier Best Newcomer award.
It was all change for Jason, who had previously worked in theatre lighting design.
He said: "I thought I would be in that job forever. It was pretty cool and good fun, but I was getting good at comedy quite quickly and I thought maybe I could do this for a living."
He's since been charming audiences as a regular on TV shows such as Live At The Apollo, Dave's One Night Stand and Comedy Rocks with Jason Manford, as well as scooping the Sony Radio Gold Award last year for "best use of an audience".
He's won fans with his high-energy live shows, complete with on-stage stunts, and after the success of last year's Cirque Du Byrne tour, he'll be back in Glasgow next month with his new show, People's Puppeteer.
He said: "I was trying to keep my uniform look with the hat and the coat, so I thought I could be a puppeteer but not do any puppetry.
"I use people as the puppets in the show, I get them on stage and get them to do things."
Jason's shows include a lot of audience participation, such as the time when he made 15 latecomers get up on stage to sing their apologies, and the Edinburgh Fringe show where he got the audience to hide when a girl had gone to the toilet.
He said: "We all went out the exit door and waited for her to come back. She came back in, as if she was having a nervous breakdown, and sat down.
"I pushed open the doors and we all screamed: 'Surprise.' The girl nearly died with fright."
When bringing People's Puppeteer to Edinburgh for its stint at the Fringe, Jason was aware that the London Olympics might mean smaller audiences.
He jokes: "It's always amazing the amount of people who come to my show, this year we still managed just under 10,000 in 12 days, so that was good.
"I thought the Olympics would really do us in."
There was, however, Olympics-inspired audience participation the night champion sprinter Usain Bolt won the 100m final.
He said: "I said to my crowd if you want to watch it I can show it on the big screen for you and they were like 'yeah.'
"So I put it on and sat down with them and we watched the race live, all 10 seconds of it.
"Afterwards one girl said 'thanks for doing that.' I think that's the nicest thing anyone's ever said to me at the festival."
He's currently staying in Edinburgh with wife, Brenda, and sons, Devlin, 12, and two-year-old Daniel.
He said: "They can't travel around with me too much due to school, but earlier this year I was in Australia for three months and they came out for one, which was nice.
"I get inspiration all around me and love thinking on my feet. When I first became a family man I started to use stuff about the kids, but my comedy changes the more mature I get.
"I'm 40, but in my head I'm not maturing at any rapid speed at all. I'm less panicky on stage and I do less running around."
He's got a busy time ahead of him with a UK tour and writing and filming a pilot of his Radio 2 sitcom, Father Figure, for BBC1, where he'll star alongside actress Pauline McLynn, who played Mrs Doyle in Father Ted.
"Acting for me is like letting a child go out and have a go on loads of slides," he said.
"Stand-up is the most terrifying thing you can do, so anything else doesn't matter."
l Jason Byrne: People's Puppeteer is at the King's Theatre, Glasgow, September 8 at 8pm. Tickets (£18.50) from the box office on 08448 717648 or online at www.atgtickets.com