Liam O’Brien doesn’t know exactly when the acting bug bit him – it was probably some time during his high school days at St. Peter’s Prep – but when it got the 23-year-old Weehawken native, it got him good. “I started acting in high school to hide from the football players,” O’Brien said. “I liked it so much that I wanted to pursue acting to the fullest. My parents kind of freaked out at first when I told them that’s what I wanted to do, but eventually, they came around.” O’Brien headed off to New York University’s prestigious Tisch Drama Program after he graduated high school in 1994. He finished the program in just three years and was ready to find the footlights. It’s just that the footlights weren’t exactly ready to find him. “I spent a full year trying to make it happen,” O’Brien explained. “People told me that I had to be patient, that it might take eight or nine years before I’d find work. I sort of freelanced, because you can’t get work without an agent and you can’t get an agent unless they see you work.” During that time, O’Brien attended an actor’s studio conceived by famed playwright David Mamet. “All of his students were my teachers, so I learned a lot,” O’Brien said. One of his teachers was actress Felicity Huffman, who currently has a starring role in the ABC sitcom, “Sports Night.” “All my teachers told me that I wouldn’t get any work for ages,” O’Brien said. “So I was all set to pay my dues.” But it didn’t take long for O’Brien to receive his first break. “One of my teachers was directing an Off-Broadway production of Harold Pinter’s ‘Hot House,’ ” O’Brien said. “I was involved with a staged reading for it and one of the producers told me that I had the part.” O’Brien was cast as “Lamb” in the Pinter play. He was on his way. “I thought it was going through the roof,” O’Brien said. “I couldn’t believe it happened so fast.” And it didn’t stop there. Soon after, O’Brien was cast in a Salt Lake City production of “The Cripple of Innishman,” where he performed for a month. He then returned home to star in a recent production of “Loot” at the George Street Playhouse in New Brunswick, which ran until last month. And last weekend, O’Brien opens in the role of Bobby in one of Tennessee Williams’ final plays, entitled “Small Craft Warnings,” which will be performed at the Tribeca Playhouse as part of the Worth Street Theater Company in lower Manhattan. The play is described simply as a few hours spent with a handful of barflies, situated in a shady gin mill in California. But it’s a setting that only a dramatic genius such as Tennessee Williams can make magical and make interesting. O’Brien’s character is a drifter from Nebraska who recalls his days with a group of runaway youngsters, experiencing romance for the first time. The play has opened to rave reviews from both the New York Times and the Newark Star-Ledger, which should secure its status for the remainder of the month. But O’Brien is already looking to further roles. He has already been signed to play Puck in Shakespeare’s whimsical “A Midsummer Night’s Dream” with the Princeton Repertory Company for the entire summer. In between, he’s doing auditions for other roles on television and in movies. “I’m very excited the way things have sort of taken off,” O’Brien said. “I’m eager to allow it to keep growing. I have to keep it all in perspective. I have to remind myself that I’ve been pretty lucky to get where I am already. I have 10 friends who are just as talented and they’re not finding work. I’m doing pretty well.” For now, O’Brien enjoys the energy he receives when he’s performing on stage. “You get up in front of 300 strangers and you don’t know what’s going to happen,” O’Brien said. “Whether they’ll like you or hate you. It’s like a big game every night. And it’s a two-way street. You give them energy and they give it back. And the audience is always smarter than you are. It’s amazing.” O’Brien would love to be a highly-respected character actor some day, in the mold of John Malkovich, who is his personal favorite. “He has his pick of roles and he doesn’t ever play the gorgeous leading man,” O’Brien said of Malkovich. “He’s able to bounce back and forth between different roles. He’s a great actor, someone I admire a lot.” O’Brien also admires his parents, who have become his biggest fans. “I owe a lot to my parents, for their support,” O’Brien said. “Them, more than anybody. I never thought it would come to this. I didn’t even think when I started. I don’t even know what I was thinking when I started acting. I still think I can’t understand what made me think I could do this.” But at this point in his skyrocketing career, O’Brien is glad he decided to take the chance that came with acting.