Joel Silver Got Robert Downey Jr. To Say One Of Avengers: Endgame's Best Lines 

Like many others, Jon Favreau believed "Iron Man" would be the final time audiences  ...

...would ever see the character on the big screen when it was released in 2008. 

As a result, he included a few endearing inside gags that weren't really ...

...intended to be carried over into subsequent motion pictures. 

One was the post-credits stinger in which Nick Fury (Samuel L. Jackson) asked Iron Man (Robert Downey, Jr.)  

to join a group named the Avengers Initiative. In interviews, 

Favreau has acknowledged that it was only intended to be a wink to fans and not a promise of future events. 

The final line of conversation in the movie was the other inside joke. Tony Stark smirked and answered, "I am Iron Man,"