Why do so many movie and TV actors also want to act onstage?

—Ellis O., Denver, Colo. A: There are many reasons—but one of the main ones is that actors love, and live, to act. Jennifer Morrison, 38, who plays Emma Swan on TV’s Once

Upon a Time ,is one of the latest to seek the stage. She recently joined the cast of The End

of Longing, written by and starring another TV alum, Friends star Matthew Perry, 47. Perry, who launched the play in London, describes it as “dark” with “a lot of swearing.” He adds, “I just wanted to write something by myself . . . and realized I was writing a play.” The play, about four people feeling the pressures of life as they meet their 40s, opens May 18 at New York City’s Lucille Lortel Theatre.