41 years ago, Sylvester Stallone gave the world Rocky, one of cinema's most durable classics; a film that holds up over time, and still inspires to this day. The actor turned 71 years old this week, and he isn't slowing down anytime soon. But, he didn't get here easily.

After all, Stallone couldn't even crack the set of The Godfather as an extra. He did go on to create a cinematic hero after all in the ring, a make believe model of himself.

A story so simple, yet so rich. The tale of a down on his luck boxer who got the chance of a lifetime. What movie audiences didn't know then was how similar Rocky was to his maker in the luck department. If Rocky had a million to one shot, Stallone's odds were even smaller. The actor is like the fictional champion in so many ways, but here's the biggest reveal: they are both fighters who have been forced to endure change and reestablish themselves.

After a roaring 1980's period that saw sequels to Rocky and Rambo and the taut 1993 thriller Cliffhanger, Stallone went into a movie slump, with his successful film average dropping below .200. When you are an action star who becomes a parody of himself, things can go bad.

Then he did the 1997 drama, Copland, and turned it around. Playing a slow-witted cop in a small New Jersey town running up against cop corruption, Stallone held his own with Robert De Niro and Harvey Keitel.

Another cinematic slump continued until 2006, which is when he gave Rocky the closure it deserved, and produced a bloody Rambo finale as well. In 2010, he wrote and directed the glorious throwback actioner, The Expendables, which spawned two sequels. However, the third film wasn't as well received as the first two, and there was another dry period where high profile work flunked at the box office or film audiences didn't approve.

In 2015, Stallone handed over the Rocky rights to director Ryan Coogler, who directed Stallone to an Oscar nominated performance in Creed. The Rocky series is one of the most persistent film franchises of all time, producing quality chapters towards the end, when repetition can come into play. Whether he is starring or directing, Stallone's fingerprints are all over the films. He is those films.

Stallone thrives off constant reinvention, going back to the well of Rocky and Rambo when he needs a bump, but not being afraid to think outside the box. And movie audiences and critics fall in love with his work all over again.

In 1975, Stallone was living in his car and striving for a place in Hollywood. He auditioned for a role in front of a couple producers and director, and didn't get the part. Before he left the room, he asked if he could leave them a script he had written about an underdog fighter named Rocky. He didn't just have to convince them to make the film, but for him to star in it as well. It was a battle, a tactic Stallone would become very good at.

These days, Sly is still making sequels and pretty doing whatever he wants to do. Whether it's showing up in Guardians of the Galaxy 2 or teasing a Creed sequel where Ivan Drago may return. He's earned that position. At 71, he no longer has to fight for his place in the movies.

Happy birthday, champ.