He also suffered the first defeat of his UFC career in his last fight - not the way any competitor wants to finish a career.
But he's also made enough money and fame to live comfortably for the rest of his life and is viewing his career from a different perspective after witnessing a brutal knockout that resulted in the death of a fellow fighter in Ireland last week.
Most inside the sport can't imagine McGregor walking away - fighters almost always hang on too long, not the other way - but he is a unique man. Still, I'm saying no.
Just this week, McGregor claimed he was as hungry as he has ever been, sending out the tweet below. Now suddenly he is walking away?
CAN THE UFC SURVIVE WITHOUT HIM?
The fallout with McGregor comes at a bad time for White and the UFC. They'd already received a ho-hum reaction to UFC 200 - and they've got serious work to do to salvage the card now.
Long-term, the impact of losing the Irishman will be just as severe. White will tell you he faced similar hysteria about how he'd replace Chuck Liddell in the early days of the promotion - and then Georges St Pierre and Anderson Silva came along.
The same questions were asked when GSP and Silva passed their primes - and then McGregor and Ronda Rousey took the sport to places it had never been.
So White will be confident he can find new stars, but that doesn't make losing the biggest one he has right now any easier, especially given the UFC has only scratched the surface of how much money it can squeeze out of the Irishman.
The UFC's broadcast deal with Fox expires in a couple of years and, in order to attract a big offer from the likes of ESPN, keeping fighters like McGregor on the roster is a must.
CAN MCGREGOR SURVIVE WITHOUT THE UFC?
McGregor's bank balance is more than healthy. UFC commentator Joe Rogan estimates the featherweight champion would have made around $5 million for his win against Jose Aldo last year, and more than that for his defeat against Diaz earlier this year.
If he wants to keep fighting, there's a thought McGregor could create his own promotional company and start headlining his own cards.
That will all depend on the nature of his contract with the UFC and whether the Irishman's ego will get the same satisfaction once he's removed himself from the spotlight the UFC provides.
IS UFC 200 RUINED?
If you'd ask any UFC fan - and Dana White if he's honest - who he expected to be headlining UFC 200 in October last year there would have been two names: McGregor and Ronda Rousey.
But after a staggering chain of events that began with Rousey being beaten to a pulp by Holly Holm in Melbourne last November and continued to Wednesday's shocking developments - those plans are out the window.
White is already working on other options - most seem to centre around the return of St Pierre to the Octagon - but it's not going to be the same.
The importance of the card to the overall performance of the business this year - keeping in mind the unexpected addition of a monumental event in New York in November - might not be as crucial as it first seemed.
COULD MCGREGOR STILL FIGHT AT UFC 200?
The idea this is all a promotional stunt to generate interest in the event in July is a little far-fetched, but that doesn't mean we can completely rule McGregor out of the card. This is the fight game after all.
The last time something like this happened, when Nick Diaz was dumped from a title fight against GSP at UFC 137 for skipping a press conference in 2011, White ended up doing an about-face.
Diaz ended up headlining the card in a fight against BJ Penn after GSP withdrew with a knee injury.
Could McGregor be recalled if he makes his apologies and White's attempts to get GSP back fail? It's certainly possible.
