While he didn't think anyone would "make a movie" about his new lease on life, the transplant had a profound effect on his outlook.
"This person, they've given me a gift that I can't ever repay to them but I can at least to the memory of what they've done for me."
Grace, who coaches Great Britain's Olympic cyclists and used to coach top New Zealand teams, was diagnosed with primary sclerosing cholangitis, a disease where the liver's bile ducts become blocked.
Over time, the body slowly poisons itself as the organ stops being able to process toxins.
Grace had the condition since he was a teenager, but it hadn't caused him any trouble until late 2015.
"In December last year I got quite ill while we were away at a race in Colombia, I had some blood tests on the day I got back and we realised something was wrong."
As the year wore on Grace felt worse and worse.
He started to struggle to get through the day, tiring after short walks, turning yellow from the build-up in his liver.
In the months leading up to his transplant, Grace was so jaundiced he bought green tinted glasses to stop people questioning why his eyes were yellow.
Despite being in poor health, with pain "like a knife between [his] ribs", Grace was determined to go to the Rio Olympics with his team in August.
Britain won the team pursuit gold ahead of New Zealand and France but even as he celebrated the victory Grace knew he had become very unwell.
On his way back home, Grace received a call in Heathrow airport telling him to come into the hospital immediately.
Blood tests sent from Rio to UK specialists indicated Grace was so sick, he might have as little as six months to live without a transplant.
Classed as a high priority patient, Grace spent seven weeks on the list before a donor was available.
"They called me from the hospital and said we've got a donor ready to go and we need you to come up here now."
Unlike some liver transplants where only part of the liver is taken, Grace has been given an entire new one, from a deceased donor.
"Somebody's lost a family member on the same day it's given me a new lease on life, it's a pretty big deal," he said of the life-saving surgery.
"It's been a pretty emotional road over the last few weeks."
Usually active, Grace has been forced to rest up while he recovers, which he says has given him time to plan what to do with the extra time his liver donor has gifted him.
"It gives you a lot of time to reflect on the kind of person you want to be and I think most importantly to be able to give the respect to the donor of the organ, to make sure you actually go out and live life and be the best that you can be."
He planned to pen a thank you letter to the donor's family, but was waiting until he felt emotionally ready.
Grace had been a registered donor in every country he'd lived in, and encouraged others to do the same.
"I thought eventually I'd be able to help someone out - for it to be other way around was pretty awesome."
Thanking his medical team, Grace said the care they took in looking after him, from diagnosis to outpatient care, had been exceptional.
"It's actually blown me away," he said.
"There wasn't any piece of the process that gave me any doubt about the staff, the processes, the systems. It's been really amazing."
Grace has been recovering at home in Manchester, home of cycling in the UK, with his wife Erika and their two young daughters after being discharged from hospital last week.
"Walking down stairs, my legs shake like I've just finished 100 sets of squats. I have to get my 10-year-old daughter to take the lid off a jam jar," he said.
"But I can feel day by day I'm getting more strength and already the new liver is working really well, all the yellow has gone out of my body."
Ever the optimist, Grace hoped to beat the 12 week recovery period estimated by doctors and be back doing what he loves, cycling, as soon as possible.
