Eve Plumb and Maureen McCormick—better known as Jan and Marcia Brady—rehearse lines on the set of The Brady Bunch at Paramount Studios on July 26, 1972.

"Didn't know anything about that," Knight said during the podcast. The first episode of "The Brady Bunch" aired in 1969. (CBS via Getty Images) "The Brady Bunch" aired from 1969 to 1974.

Williams and his partner Peta Murgatroyd performed the second routine of the night to “It’s a Sunshine Day,” the 1972 song performed by the Brady Bunch and featured in episode 16 of Season 4 ...