10 Things You Probably Didn't Know About 'Iron Man'

Marvel is on a big roll, what with "Avengers: Age of Ultron" making more than a billion dollars worldwide. Seven years ago, the whole Marvel Cinematic Universe all started with "Iron Man."

But how much do you really know about "Iron Man" and how it was made?

Did you know that Agent Coulson was originally supposed to just be a bit part?

There's also this little easter egg that fans of the comics might have caught:

Or, if you grew up watching the "Iron Man" cartoon, you might have recognized this little ditty:

This is one for the programming enthusiasts out there:

Can you imagine anyone other than Robert Downey Jr. playing Tony Stark? We can't. But we almost got a movie with Clive Owen or Sam Rockwell in the role:

Here's a little behind-the-scenes fact that will make you glad you weren't an extra on the film:

Other extras had better conditions, but were just being lied to a lot:

The motion-capture people sounded like they had fun though:

Editor Kyle Cooper threw some cuteness into that montage at the beginning of the movie:

Oh, and if you were wondering how they did that scene where Pepper reaches into Tony's chest, here's the answer: