He’s an endless ball of energy, and Robert Downey Jr. was on top of his game as usual at a special screening of “Iron Man 3” in London, England today (April 18).

Joined by his beautiful wife Susan Downey, the “Sherlock Holmes” hunk was as animated as ever in a strange pair of black-rimmed glasses teamed with a snazzy black suit as he mingled with famous folks like Sir Ben Kingsley, Don Cheadle, Samantha Barks, Rebecca Hall, and Stanley Tucci.

In the latest issue of GQ, Robert discusses the massive $50 million paycheck he took home from “The Avengers” last year, after all bonuses and residuals were tallied.

Downey gushed, “Isn’t that crazy? They’re so pissed. I can’t believe it. I’m what’s known as ‘a strategic cost.’”