Hamm's high-school girlfriend's older brother's college roommate was an eager actor named Paul Rudd. Hamm fell in with Rudd and his gang and visited them in L.A. in 1992, crashing in their "shit-hole North Hollywood apartment" during the spring break of his junior year. He came out for good in 1995. "At a certain point," he says, "I figured I was way too far down the line for a normal career. I was waiting tables with a friend who had been a business major, and he really wanted to get this job selling copiers. I just thought, 'Really? You really want that job?' My dad was a salesman. He could sell anything to anybody. I was like, 'Nah, not for me.'" Hamm arrived in Hollywood just in time for the reign of the CW and the WB. "If you didn't look 18 years old, you weren't working. And I didn't look 18 years old when I was 18. I always looked 10 years older than I was."

Really, though, Hamm was never in danger of taking the easy route. "L.A. represents opportunity," he says. "And, as has been proven over and over in the current media landscape, it doesn't take much for them to put you on TV. If that's all you want, you can be on The Bachelor or The Real Housewives or whatever show just wants oversized personalities, ridiculous behavior, and zero dignity."

But don't you need a burning desire to break through? To be crazy enough to think you can show up and be anointed for fame?

"I don't know," Hamm says. "When you try to learn how to act, you approach it with respect. But if you just want to be famous . . . that's not that much different than porn. 'I'm a movie star!' Well, no, you're not. You're a porn star, and that's completely different. And you know, hey, mazel tov—porn probably built half the houses out here, but you're selling your dignity in a way that I feel I'm not. And once you sell it, it's gone. You ain't getting it back."

There are certain tones that Hamm strikes—whether by accident or by force of habit—that lend his casual pronouncements the feel of a Don Draper delivery. Sometimes it's the purse-lipped, tight-jawed verbal sneer. Like when he says: "And once you sell it, it's gone."

Then there's the salesman's pitch, a dreamy melody of wishes granted, promises met, futures brightened. So, after another triple-digit speed dash, he can say with languorous authority, "The thing about this car is, it has excellent brakes," and it is utterly convincing.

And when we stop for a snack down the road at a place called Duke's and Hamm pronounces a phrase as banal as "The nachos have landed," it has the weight of a benediction. Everything's gonna be all right now, because . . . the nachos have landed.

Hamm tries to steer the SLS into an inconspicuous corner of Duke's lot, but we are redirected by the pimply attendant to a space of honor, front and center. The truth is, gleaming ride and all, not many people take notice of him. Maybe it's some Malibu nonchalance. Or maybe this particular mélange of weekend bikers, cheeseburger-in-paradise burnouts, and affluent Spanish tourists isn't a prime Mad Men demographic. More likely it has to do with how little Hamm resembles his onscreen persona: He's an athletic guy with a quick smile, floppy hair, mouse-gray Nike mid-tops. Not self-consciously handsome. Not a dick. A normal guy—normal in the way you get by leading a normal (by this town's standards) life right up until you get the part that changes everything.

A smiling brunette approaches apologetically. Here we go. Cover blown. "Are you guys using that stool?" she asks. False alarm.