#2 Daniel Bryan had to be fired from WWE twice before he made it big
The story of Daniel Bryan/Bryan Danielson's path to WWE success has been told a million times just in Sportskeeda articles alone. So, let's do the condensed version, just to save time. Also, here's a song about Bryan from the band Cheap Pop.
Bryan began his career in 1999 after training at a school co-founded by Shawn Michaels. He signed a deal with WWE in 2000 and worked in their developmental territories for 18 months before being released. Then, he went to Japan and then Ring of Honor and destroyed everybody and was eventually resigned by WWE.
Then, he was on the first season of the "Game Show" iteration of NXT and was eliminated. He returned as part of Nexus but was then fired for choking ring announcer Justin Roberts with his own necktie during the group's debut. That wouldn't last long, however, as Bryan was brought back to the company just months later at SummerSlam as a surprise member of Team WWE to help take on his former Nexus buddies.
At this point, the rest of this entry would just be "the history of Daniel Bryan in WWE", and you can just go to Wikipedia and read that. But, Bryan is an interesting case because this isn't a situation of a wrestler being released and then stepping up their game and coming back. Bryan was released a second time and continued to be awesome (no pun intended) and then WWE came back and said "errr... OK, we goofed, please come back and work for us."
It's a very satisfying story.... but not nearly as satisfying as this one...