Who said "I can't do this forever."?

This quote is attributed to Iron Man (The Avengers).

I can't do this forever. - Iron Man (The Avengers)

"I can't do this forever."

Iron Man (The Avengers)

"I am Iron Man."

"Genius, billionaire, playboy, philanthropist."

"If you're nothing without the suit, then you shouldn't have it."

"I've successfully privatized world peace."