The Wales full-back was in unstoppable form at Sydney's ANZ Stadium, breaking two British and Irish Lions records as Australia were swamped 41-16. Halfpenny's 21-point haul is a Lions Test record, while his 49 points in the series beat his goalkicking mentor Neil Jenkins' previous best of 41, set 16 years ago.
But it was his last-gasp penalty miss last weekend that drove him on. "I had to put it behind me, but I also used the experience. I didn't want to feel like that again," Halfpenny said. "I used it as a motivation because the disappointment can stay with you. I wanted to be a part of a Lions series win, and it helped me today."
He added: "It was hard after the game, I was pretty down. It was tough, really tough. I had the chance to win it for the Lions and I didn't take it. That is what all the hard work is for, for moments like that. I was devastated at not being able to do it.
"It was touch and go, that kick. I felt if I connected with it I would make it, but I didn't connect and it took me a few days to shake it off. But we had another chance, and people made that clear to me we had another chance. Not often in sport do you get a second chance."
Among the well-wishers in the Lions dressing room afterwards was James Bond actor Daniel Craig, and Halfpenny admitted the whole experience was a surreal one.
"I didn't realise he (Craig) was in the changing room. But it was incredible to see James Bond in there," Halfpenny added. "I guess it shows you what it means.
"The contrast in dressing rooms after games can always be extreme. Last week was as low as I ever want to feel, but this is just incredible. I had the chance to win it in Melbourne - we had the chance to kill it there. We weren't able to do that, and it was a case of picking ourselves up and dusting ourselves off.
"We had a few days break to relax, and that really helped. It has been a long tour and that helped us refresh.
"As a kid you have a dream of pulling on a Lions jersey. But I never dreamt of anything like this. To play like that and win like that is something that will live with me forever. It's amazing to be a part of a Lions Test series win".