Even Britney Spears wonders what she was thinking

If you're wondering what was going through Britney Spears' head during her erratic era, you are not alone — so does she.

"I sit there and I look back and I'm like, 'I'm a smart person. What the hell was I thinking?'" Spears said in an interview to air on MTV on Nov. 30, two days before the release of her new album. "I've been through a lot in the past two or three years, and there's a lot that people don't know."

The 90-minute special, "Britney: For The Record," was executive-produced by Spears' manager Larry Rudolph. It features behind-the-scenes footage of the singer and her talking about her life over the past two years.

She's got a lot to talk about: In that time span, she has gotten divorced, been through a custody battle, gone to rehab, had very public meltdowns and had one memorably bad performance at the MTV Video Music Awards.

Now on the comeback trail, Spears is releasing her sixth album, "Circus," on Dec. 2, her 27th birthday.

Spears says she's hoping this TV special will "set the record straight" about her life.