He reprises his role as the eponymous former CIA assassin, now in a “post-Snowden world” where the line between protecting personal privacy and state security is regularly crossed, particularly in the case of social media.
The father-of-four confessed he was a “dinosaur” who avoided sites like Twitter and Instagram but said he was glad they were not around to capture the indiscretions of his youth, unlike for step-daughter Alexia, 17, and daughters Isabella, 10, Gia, seven, and Stella, five.
He said: “I do worry about my daughters on social media.
“We talk about it, and I’m not on these things, I’m kind of a dinosaur, but it’s scary to think that some kind of teenage mistake — something I could have done, and millions upon millions of people do foolish things as teenagers — could somehow follow someone around forever. That’s a really scary thing.
“Kids are supposed to be making mistakes in adolescence, that’s what it’s for, make those mistakes in the safety of your adolescence and bring a little more wisdom into adulthood, but I definitely worry about it.”
Being well into adulthood had one big disadvantage for Damon when filming.
The 45-year-old admitted he struggled a lot more with the stunts required for his fourth film in the franchise, having started on the Bourne Identity when he was 29.
He said: “They were much much harder, everything was harder.
“Just getting into shape was an up-at-dawn-siege everyday and the diet, the strict diets, that was the hardest part.
Jason Bourne is in Irish cinemas from July 27.