Retna Digital

Entertainment Tonight -- Drew Barrymore says she gave up her cell phone for a very important reason.

The actress didn't use the phone because she was so dedicated to her character "Little" Edie Bouvier Beale in HBO's upcoming "Grey Gardens," which is set in the '70s and is based on the lives of the eccentric aunt and first cousin of Jackie Onassis.

"I felt I had to isolate myself," Drew tells Gotham magazine. "It was really painful for me not to have contact with the people I love. I felt like it would be fraudulent to talk on a cell phone -- 'Like, yeah, I'll call you back in a second' -- and walk back on set and pretend I'm this person who wouldn't even know what a cell phone was."

Meanwhile, the actress reveals how she's triumphed over difficult times, saying, "I try to realize what and who's important. What's important is being good to people I love and earning their respect and being available to them physically and emotionally. That's my biggest and only priority, and the rest of it you just can't control."