I posted this in the Niki Lauda thread when he passed away, so it's just a copy paste.
He just had massive balls of steel in general and his perseverance and "never give up" mentality is what made him a legend.
He cut ties to his wealthy family after his grandfather interfered and blocked him from getting sponsored by the Austrian bank as he wanted to stop him from racing when he was just starting out; Niki went on and took out numerous loans to finance his racing career.
He told Enzo Ferrari that the car he was supposed to drive was shite.
He told the priest who was giving him his last rites after the crash in the hospital to fuck off because he wasn't dead and that made him so angry that it inspired him to fight harder to stay alive.
He underwent extremely painful lung-cleaning procedures (among other severe injuries) and returned to racing just 42 days after the crash with unhealed burn wounds and still managed to qualify 5th and finish 4th in the race.
He boycotted the last race in Fuji in the 76 season due to safety concerns; drove only one lap and left the circuit, willingly giving up his championship hopes to protest risking drivers' lives over TV contract.
He stood up against Boeing and made them acknowledge their technical fault after a plane belonging to his airline had a fatal crash in Thailand. To do that, he ran numerous flight simulations and offered to fly on a 767 with two pilots and repeat the scenario to see if the accident could have been prevented by the pilots.
He came out of retirement and won his 3rd title.
He survived two kidney transplants.
Death only managed to take him while he was asleep.
Legend.