Russell Brand says Katy Perry who? The Get Him To Greek star famously went to rehab for sex addiction and has been very open about his drug use and drinking, but never before mentioned that his memory might have been affected.

Brand has been eschewing much of the mainstream media for political off social commentary lately, but he did sit down on "Live with Kelly and Michael" to explain Thanksgiving to a bunch of kids.

The "Arthur" star asked the children who they might want to see nibbling giblets with them on the holiday when one threw out an invitation to Russell Brand's ex-wife, Katy Perry.

This threw the 39-year-old comedian for a loop.

"Katy Perry?" he asked. "I don't know who that is!"

Brand closed the program by saying "Thanks to these Americans, I, Russell Brand, an Englishman, and a hurtful mention of my ex-wife, I, Russell Brand have a much better understanding of Thanksgiving, the tradition."

Brand and Perry met at the 2009 MTV Awards. They got married a year later in India in a private Hindu ceremony on October 23, 2010. Russell Brand's high-profile celebrity marriage to the megapopstar Katy Perry ended in 2011 after just 14 months. Their divorce was finalized in July 2012.

To jog Brand's addled memory, Katy Perry will headline the Pepsi Super Bowl halftime show on Feb. 1.

The Katy Perry Super Bowl news was confirmed by the NFL on Sunday. Perry, was watching the New York Giants play the Dallas Cowboys and immediately took to Twitter to gush "My band is in the other room screaming at the TV (and each other) over this Cowboys-Giants game. Can't wait for February 1st."

In a video Katy posted after the announcement, Perry said "I've got some insane ideas this year. What if we covered the stadium with glitter? But the glitter ... was edible."

Perry latest album, the hypnotic Prism also went platinum on the strength of the No. 1 hits Roar and Dark Horse.

The Super Bowl is America's most-watched TV event.

Perry is out on the road at the moment on her Prismatic World Tour.