Lomu told the Daily Mail that if he sees Brayley, six, and Dhyreille, who will be five this week, reach the age of maturity, if he can get to the age of 55, he will consider himself a lucky man.
"My goal is to make it to the boys' 21sts," Lomu told the Daily Mail. "There are no guarantees that will happen, but it's my focus. It's a milestone that every parent wants to get to. My dad died young and that makes you think. I want my boys to be healthy and if they get to 21, they should be fit and healthy and live a normal life."
Lomu is hooked up to a dialysis machine three times a week, six hours a day, and the machine takes blood from his body, cleanses it of the impurities that his diseased kidney cannot and then pumps the blood back in.
Since his new kidney failed in 2011, Lomu has been desperately hoping for the chance of a second transplant. He knows, though, that the reality is that his body is much more likely to reject a second transplant than a first. Physically and mentally, the dialysis is exhausting. Lomu tries to catch up on emails during his six hours of stillness. Or he watches movies. It is a fight not to become dispirited and despairing.
"You have to try and stay up and be happy and positive about it,' says Lomu. 'Because I will tell you one thing: it does get you down at times. It's difficult. Every dialysis patient is different but we have one commonality: we have no other choice. Your second choice isn't really a choice. It's just you giving up."
"When I look in the mirror, what I see is my two sons. They're my priority. The two boys were miracles. Medically, it wasn't supposed to happen because of my kidney stuff. Never in my wildest dreams did I ever think I'd be a dad.
"Now, when I wake up in the morning, instead of looking in the mirror and thinking, "What am I going to do today?" I look in the mirror and think, "I've got the two boys, now get yourself up and get yourself moving and try to be the best dad you can be".