Actor Michael K. Williams is busy these days.

He's featured in the latest “Ghostbusters” movie; has his own series, “Black Market,” on Viceland; is appearing in HBO's new series “The Night Of”; and has a role in the action flick “Assassin's Creed,” set to be released in December.

But when you see him, it's hard not to think of his role as Omar on HBO's “The Wire.”

Williams, recently on Stephen Colbert's “The Late Show,” talked about how his portrayal of the shotgun-wielding, whistling Baltimore-based stickup man changed his life.

“I equate my years with the cast of 'The Wire' as being like my college years. I learned the business, from financially how to manage my money better [to] how to ride a character out for a period of time,” he said.

Williams said playing Omar gave him more confidence.

“I had a very low self-esteem growing up, high need to be accepted. I was a corny kid, you know, in the projects,” Williams said. “And so all of a sudden, [as] Omar, you know, I'm getting the respect from people that probably would've taken my lunch money as a kid.”

—Brittany Britto