Sometimes, as the old maxim goes, it's not what you know, it's who you know. Bryan Greenberg knew the right guy when it came to landing the lead role in the HBO comedy series “How to Make It in America,” which premieres Sunday. He just didn't know that he knew him.

“I knew the creator, Ian Edelman,” Greenberg says. “I played basketball with him. I didn't even know he was a writer. I was reading in the trades that he had this pilot that he was doing for HBO, and I was like, ‘I want to read this.'”

It's a good thing he did. Greenberg, who has spent the better part of the past decade acting on the series “One Tree Hill,” “Unscripted” and “October Road” and in films such as “Bride Wars” and “Prime,” calls the new gig his dream job. On the show — which co-stars Victor Rasuk, Luis Guzman, Lake Bell, Shannyn Sossamon, Eddie Kaye Thomas and Scott “Kid Cudi” Mescudi — he plays Ben Epstein, a Brooklyn 20-something who hustles his way through life while trying to make it in the New York fashion scene.

“He's at the place in his life where his peers have gone on and become successful, and he's definitely not happy with where he's at in life, and I think a lot of people can relate to that,” Greenberg says. “His ex-girlfriend left him because he's not happy. He's working at Barneys folding jeans every day. He's basically miserable.”

Before anyone starts feeling too sorry for Greenberg's character, it should be noted that he's not miserable in the true sense of the word. He's miserable only to the degree to which a good-looking young guy hanging out with the hipster elite in Manhattan can be miserable.

“He's a cool kid,” Greenberg says. “He can get into all the clubs, he can get into all the parties, he's well-connected — but he's broke. It doesn't mean anything to him anymore. He's kind of over it.”

He may not have money, but he's got style. And by the end of the pilot episode, it seems fairly evident that if he's going to better his situation, that's going to be his ticket. It's not the show's, though. There's more to “How to Make It in America” than cool clothes and connections. While there is a fashion element to the show, Greenberg says it's strictly street fashion, not high-end fashion.

While it took a little help from guys like Mark Wahlberg and Edelman for him to get into the position he's in today, Greenberg says that ultimately his dream job on “How to Make It in America” — like the show itself — is all about living the American dream.

“This country allows you the opportunity to make whatever you want of yourself. It's not biased in that aspect,” he says.