Mac Miller is in love. He’s glowing, and it isn't just the August sun beating down on the back patio of a trendy Burbank coffee house. The 24-year-old rapper’s eyes are vaguely obscured under a blue Polo cap, but they still have a sparkle that rivals the diamond studs in his ears. His whole vibe is loose and easy, mimicked by his sagging jeans and Adidas slip-ons. The socks match the tee: plain, white, no fucks. And he's grinning, a lot. Like, a lot a lot. So what, exactly, is the source of all this radiant glee?

"Trees! Plants! Like, the outdoors, man," says Mac. "It's like the planet is a giant playground and I've been too small to ride all the rides until now. Lately, I've been running around like a chicken with his head cut off, just loving being outside in the sunshine. I'm overwhelmed with things to do. People are like, 'What do you have to do today?' I'm like, 'Get outta the house and into the car! It's gonna be a great day!'"

He yells this last part like Chevy Chase in character as Clark Griswold, so it could be the espresso talking. His order, for "Malcolm" (last name McCormick), called for eight shots over ice. Or it may be what the coffee replaced—Mac is 61 days clean and sober (he calls espresso his "new DOC," or drug of choice). Or that he's moving back from New York to Los Angeles, where the Pittsburgh native musically came of age four years ago. Or that his new album, The Divine Feminine, out September 16 via Warner Bros., finds him singing (singing!) songs about love (love!). Or, yes, it may have something to do with his budding relationship with Ariana Grande. It's probably a bit of everything.