Sometimes TV can sneak up and surprise you. Viewers may tune in to “Sex Rehab With Dr. Drew” expecting to laugh at a bunch of train-wreck quasi celebrities whining about their sex addiction, a problem that most people find funny all by itself.

But “Sex Rehab,” which is a spinoff of VH1’s successful reality series “Celebrity Rehab With Dr. Drew,” will actually make viewers sympathize with and even root for most of the eight oddballs who have agreed to undergo treatment for 21 days at the Pasadena Recovery Center.

In the pilot, premiering on VH1 on Sunday, Nov. 1, at 10 p.m., we see the future patients going about their routines as they prepare to enter rehab. One, a champion surfer named James Lovett, is watching a porn video on his GPS as he drives around town. He tells the camera, “I lost all my sponsors and my friends due to sleeping with their wives.”

Another, the Skid Row drummer Phil Varone, claims to have slept with 3,000 women. He says that he’s incapable of forming a long-term romantic relationship.

Some of the women have an extraordinary number of sex toys. A porn actress named Penny Flame tries to smuggle a device she has named Ron Jeremy into rehab.

Many of the women are famous for being infamous: The Playboy centerfold Nicole Narain appeared in the Colin Farrell sex tape; the porn actress Kendra Jade reportedly was involved with both Jerry Springer and Kevin Federline; and Kari Ann Peniche, a former Miss USA Teen and Playboy model, was the other naked woman in the tape shot by the “Grey’s Anatomy” actor Eric Dane.

Probably the biggest star is the actress and model Amber Smith, who says that when she cured her opiate addiction by appearing on “Celebrity Rehab,” she replaced it with the compulsive pursuit of men.

She’s not the only one with a reality-TV connection. Kendra Jade is married to Lukas Rossi, the winner of NBC’s “Rock Star Supernova,” and Kari Ann was briefly engaged to the pop star Aaron Carter, who’s currently working out his own issues on “Dancing With the Stars.”

Most of this absurdity is front-loaded in the premiere, and gradually, despite ourselves, we start to see these characters as real people with real problems. In one-on-one and group sessions, Dr. Drew (né Pinsky) gets the patients to open up about their pasts.

Many of them say they were sexually abused as children. Penny says that she first had sex at age 12 and then turned around and started molesting other children.

After one group session, Phil says that he’s worried because he doesn’t have any traumatic childhood stories to share, but he earns his camera time by talking about the huge crush he has on Amber.

By the end of the first two episodes, some of the patients seem to be heading in the wrong direction. We see James compulsively running on a treadmill like a hamster on a wheel. Kari Ann starts to chafe under the discipline and lashes out at the staff.

Even viewers who know about the manipulations routinely practiced by reality TV will likely find themselves caring what happens next. As a tearful Penny says at one point during a therapy session, “You’re good, Dr. Drew.”