Sometimes, it's as simple as rallying from behind to win - other times, it's as hard as turning your career (or life) around to return to the top.
The Newshub panel of experts look back on a huge year of sport that produced some thrilling comebacks.
Sullivan Harnett (Newshub reporter): Belgium 3 Japan 2 at the Football World Cup
In the round of 16, the Japanese found themselves 2-0 up with just 22 minutes to go.
On the biggest stage in the world, Belgium picked themselves up from the cusp of elimination and scored three goals in the final 20 minutes to snatch victory and move on to the quarter-final.
Defender Jan Vertonghen scored in unlikely fashion, after a long-range header found the back of the net to give the European side a glimmer of hope.
Marouane Fellaini scored a header off an Eden Hazard cross to level the game and Nacer Chadli completed the comeback in stoppage time, after a length-of-the-field counterattack.
The dream was still alive, thanks to one of the greatest comebacks in World Cup history.
Ollie Ritchie (Newshub sports reporter): Tiger Woods wins the 2018 Tour Championship
Personal issues and injury have kept Tiger Woods silent on the golf course for the past few years, but in the Tour Championship, we saw the Tiger Woods of old.
His first PGA win in five years, following a very public fall from grace, this was a comeback of epic proportions.
Four back surgeries, personal issues, an arrest in Florida and a run of poor form saw the Tiger Woods we used to know and love, slip further and further away.
Was there a more engaging picture than Woods walking to the 18th hole, surrounded by thousands of fans captivated by his every move.
Seeing Woods back in the winner's circle was good for the game, good for the fans - and good for Woods.
Andrew Gourdie (Newshub sports presenter): Tyson Fury returns to the ring
Two-and-a-half years out of the ring, drink, drug and mental health problems, 60kg overweight - Tyson Fury was done.
To overcome all of that, lose the weight and climb back into the ring to take on the most feared fighter on the planet - Deontay Wilder - was sensational.
"I just showed the world tonight, everyone suffering with mental health, that you can come back and it can be done," he said. "Everybody out there who has the same problems that I've been suffering with, I did that for you guys."
The judges called it a draw, but Tyson Fury is still a champion and an inspiration.
Brad Lewis: Scott McLaughlin wins the Supercars Championship
To pull himself off the tarmac after his 2017 choke, McLaughlin showed the motorsport world what he was made of, scoring a stunning Supercars series title.
McLaughlin dominated the championship battle, until a late-season slip in performance allowed Kiwi countryman Shane Van Gisbergen to sneak in front.
But McLaughlin stuck to his guns, raced like a cerebral assassin, got the lead back and his performance on championship Sunday was a year in the making.
Luke Robinson (Newshub online sports producer): Sam Gaze wins Commonwealth Games mountain bike gold
Sam Gaze and Anton Cooper did battle on the Gold Coast in a fantastic competitive race throughout. With just over a lap to go, Gaze had to enter the pits to fix a puncture, with Cooper attacking immediately.
An angry Gaze got back on his bike and somehow managed to claw his way back in just half of the 4.5km lap, setting up a showdown between the rival Kiwis.
Gaze chased him down and elbowed his way past Cooper to avenge the demons of his silver medal four years earlier.
BL: All Blacks beat South Africa in Pretoria
Down by 17 points with 18 minutes on the clock, the All Blacks produced a trademark comeback to deny South Africa back-to-back wins against the world champions.
New Zealand had no right to win a game that they failed to lead until the final play.
The Springboks held 23-6 and 30-13 leads in the second half, but they couldn't hang with New Zealand's fifth gear in the final quarter.
Ardie Savea's 79th-minute try levelled the scores, before Richie Mo'unga ended the game with a handy conversion to break South African hearts.
Newshub.
