Just about every comic book fan out there knows who Jim Lee is. He’s not only one of the most popular artists around, he’s also the DC Entertainment Publisher & Chief Creative Officer. But the road to success is often a difficult one, and it was no different for Lee.

#ShareYourRejection was trending on Twitter, so Lee tweeted four rejection letters – two from Marvel, two from DC. While the DC ones simply said he did not meet “current DC standards,” there was at least a bit of positive feedback with a handwritten note saying “some interesting stuff, keep at it!” Marvel, on the other hand, was more elaborate in its feedback. One letter shared some very blunt constructive criticism, while the other Marvel letter was a polite rejection without offering feedback (and apologizing for not having the time to doing so). Read the letters below.

He tweeted that he would run around his school’s track “Rocky style” while thinking about Frank Miller and John Byrne’s work. Obviously, Lee didn’t give up and he went on to illustrate comics for both of the big publishers while also moving up DC’s corporate ladder. Lee has a vast resume of work, but he’s often known for his work on the X-Men and Batman.

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To give me focus during the time I tried to break in, I would work out and run around a local high school track—Rocky style—chanting sotto voce, out of breath— “Miller, Byrne, Miller, Byrne…” #ShareYourRejection pic.twitter.com/J5RJw7jJjx

— Jim Lee (@JimLee) August 18, 2018

Moral of the story? If you’re truly passionate about something, keep at it. Maybe one day you’ll reach the top, just like Lee.