The 46-year-old English director opened up in an interview with Metro about his highly-publicized 2012 fling with the 26-year-old actress, who starred in his movie Snow White and the Huntsman.
"You never know what's coming in life," Sanders told the publication. "Around every corner there's something unexpected, and that's life. You just have to brush yourself off and continue moving forward the best you can."
"Everyone makes mistakes," he added. "I am bound to make more mistakes and I wouldn't expect my life to be exciting if I didn't."
Sanders was married to Liberty Ross when Us Weekly published photos in July 2012 of him kissing Stewart, then 22. The incident followed the release of Snow White and the Huntsman, but the director was not asked back to helm the sequel.
"If you took people off the table for a momentary lapse, there would be no one making art," he told Metro.
Ross, who shares daughter Skyla and son Tennyson with Sanders, filed for divorce from the director in 2013. Stewart also split from her Twilight co-star Robert Pattinson, whom she was dating at the time of the affair.
"The public kind of burned me at the stake," the actress told Marie Claire in 2015 of fan reaction to the scandal. "At one point, you just let go and give yourself to your life."
Sanders' first feature film since the affair, an adaptation of the Japanese manga Ghost in the Shell, opened in theaters Friday. The movie, which was plagued by whitewashing claims, stars Scarlett Johansson.