Thirteen years ago, Orlando Bloom nearly lost his life -- and his career.

While trying to climb a rooftop terrace with friends, the then 21-year-old fell three stories when the drainpipe he was scaling collapsed. Breaking several vertebrae in his back, Bloom was paralyzed for four days.

"I'm grateful for it," Bloom, now 34, tells the October issue of Men's Health. Following multiple surgeries and 18 months of rehab, Bloom was able to resume his acting career, beginning with 2001's The Lord of the Rings: The Fellowship of the Ring.

"I'm always working on my back," the British star says. "It hasn't prevented me from doing anything. But it's a constant reminder."

In fact, the accident helped the actor -- married to supermodel Miranda Kerr -- gain a new lease on life.

"Fear is not a friend of mine. But it's something to have a healthy awareness of," he tells Men's Health. "[But] I can't stop living. It would ruin my creativity, the person I am."