And this month he has two movies in cinemas: The Legend of Tarzan with Alexander Skarsgard, Margot Robbie and Christoph Waltz, and the Stephen King thriller Cell opposite John Cusack. He's philosophical about his hectic work schedule. "Painters get up and paint. Writers get up and write. I get up and create characters," he explains. "I like creating. It fuels me. And it's doing something that keeps me from being me all day!"

Samuel L. Jackson at the Legend Of Tarzan premiere

This helps explain why he appears in such a wide range of movies. He says that when Quentin Tarantino or Spike Lee call, he automatically says "yes" (last year he starred in Tarantino's The Hateful Eight and Lee's Chi-Raq). "Otherwise, there are times that I choose a movie because it's something I would have gone to see when I was a kid," he says, referring to the Star Wars pequels, the Marvel movies, his Shaft remake or the madcap action of Snakes on a Plane. "So with Tarzan, I always wanted to be in that movie. Here's the chance, hell yeah! Let me be in that! It's still the thing that drives me. I'm still doing the movies I was pretending to do as a kid."

And he's known for taking each role seriously, writing a character biography to better understand who he's playing. Jackson explains what he puts in these bios: "The kind of foods that he eats, educational background, parents, the kind of friends he had, the kind of friends he developed, how he started making money, how he made his money, what he did with it, what gives him his confidence, how he's managed to make his way through the world."

And he's especially atuned to personal defects. "In Kingsman, I did the lisp because people tend to dismiss people who have defects, especially speech defects," he says. "I stuttered when I was a kid. People laughed at me when I talked. Smart people."

He's thankful for those who encouraged him and gave him such a strong work ethic. "I grew up in a house of people where, when I woke up every day, everybody was going to work," he says. "And I thought that's what grown people did. And they didn't even have jobs they liked! I got a job I love, you know? If actors could get up and go somewhere every day and act, I guarantee you they'd be the happiest people in the world. And I am."

Watch the trailer for The Legend Of Tarzan: