Brendan Marrocco is the first soldier to survive losing all four limbs in the Iraq War. He had arms attached and has undergone weeks of round-the-clock medical care.
Wounded by a roadside bomb in 2009, the former soldier said he could get by without legs, but he hated living without arms.
"Not having arms takes so much away from you. Even your personality, you know. You talk with your hands. You do everything with your hands, and when you don't have that, you're kind of lost for a while," the 26-year-old New Yorker told reporters Tuesday at Johns Hopkins Hospital.
Doctors don't want him using his new arms too much yet, but his gritty determination to regain independence was one of the chief reasons he was chosen to receive the surgery, which has been performed in the U.S. only seven times.
That's the message Marrocco said he has for other wounded soldiers.
"Just not to give up hope. You know, life always gets better, and you're still alive," he said. "And to be stubborn. There's a lot of people who will say you can't do something. Just be stubborn and do it anyway. Work your ass off and do it."
Dr. W.P. Andrew Lee, head of the team that conducted the surgery, said the new arms could eventually provide much of the same function as his original arms and hands. Another double-arm transplant patient can now use chopsticks and tie his shoes.
Lee said Marrocco's recovery has been remarkable, and the transplant is helping to "restore physical and psychological well-being."
Tuesday's news conference was held to mark a milestone in his recovery: the day he was to be discharged from the hospital.
Next comes several years of rehabilitation, including physical therapy that is going to become more difficult as feeling returns to the arms.
Before the surgery, he had been living with his older brother in a specially equipped home on New York's Staten Island that had been built with the help of several charities. Shortly after moving in, he said it was "a relief to not have to rely on other people so much."
The home was heavily damaged by Superstorm Sandy last fall.
For the next few months, Marrocco plans to live with his brother in an apartment near the hospital.
The former infantryman said he can already move the elbow on his left arm and rotate it a little bit, but there hasn't been much movement yet for his right arm, which was transplanted higher up.
Marrocco's operation also involved a technical feat not tried in previous cases, Lee said in an interview after the news conference.
A small part of Marrocco's left forearm remained just below his elbow, and doctors transplanted a whole new forearm around and on top of it, then rewired nerves to serve the old and new muscles in that arm.
He also explained why leg transplants are not done for people missing those limbs - "it's not very practical." That's because nerves regrow at best about an inch a month, so it would be many years before a transplanted leg was useful.
Even if movement returned, a patient might lack sensation on the soles of the feet, which would be unsafe if the person stepped on sharp objects and couldn't feel the pain.
The Associated Press contributed to this report.