Joseph Kosinski is exceptionally humble about “Top Gun: Maverick.” Paramount’s action-packed blockbuster, featuring Tom Cruise’s return to the skies 36 years after the original film, has become an unexpected sensation, bringing audiences young and old back to the big screen at a time when theaters are in desperate need of a win. In the process, “Maverick” has racked up an eye-popping $1.4 billion globally to stand as the highest-grossing movie of the year. Nobody has been more surprised by its success than Kosinski. “I don’t know if I’ve wrapped my head around it. I’m amazed every day that it continues to play,” he says. The film, available on home entertainment on Aug. 23 at a premium price, has remained in the top five on domestic box office charts for 12 of its 13 weeks of release.