#2 Almost quitting WWE in 2012 after his first match back
Brock Lesnar's first match back since his return was at Extreme Rules 2012 but it could have all ended there. Brock was booked to lose the match, which he was, of course, aware of. However, according to reports at the time, after the match was over, Lesnar was supposed to absolutely destroy John Cena which would lead to Cena getting taken out of the arena in a stretcher.
Instead, after the match was over, Cena got up and cut an impromptu promo where he hinted at leaving the ring and retiring. Lesnar was furious at how things had played out and threw a fit backstage, threatening to leave the company after just one match into his run.
Where other WWE stars would have been fired or at the very least punished and fined for their behavior, Lesnar was booked for a monstrous push and totally destroyed John Cena in their next meeting.