Poised and upbeat, he told audience members at his movie premiere, "I've been blessed to have the opportunities I've had. It couldn't have happened better. I'm stoked."
Although he vowed to "take it back to college" at the film's fraternity-themed afterparty, he quietly mingled with the crowd, and when asked about his favorite beer at a later event, he named nonalcoholic O'Doul's.
It's a significant turn-around for the 26-year-old star, who also presented at the Oscars on March 2 – his most high-profile appearance since a rough 2013, in which he underwent rehab last spring and broke his jaw in November when he fell at his L.A. home.
These days "I couldn't be happier," Efron told PEOPLE in January while promoting his comedy That Awkward Moment. "I'm in a great place."
For much more on Zac Efron's life after rehab, pick up the new issue of PEOPLE