
Research chemist Barnaby Fulton works on a fountain of youth pill for a chemical company. One of the labs chimps gets loose in the laboratory and mixes chemicals, but then pours the mix into the water cooler. When trying one of his own samples, washed down with water from the cooler, Fulton begins to act just like a twenty-year-old and believes his potion is working. Soon his wife and boss are also behaving like children.

Cary Grant
Barnaby Fulton

Ginger Rogers
Edwina Fulton

Charles Coburn
Oliver Oxley

Marilyn Monroe
Lois Laurel

Hugh Marlowe
Hank Entwhistle

Henri Letondal
Jerome Kitzel

Robert Cornthwaite
Dr. Zoldeck

Larry Keating
GJ Culverly

Douglas Spencer
Dr. Brunner

Esther Dale
Mrs. Rhinelander

George Winslow
Little Indian
Marjorie Holliday
Oxley Receptionist (uncredited)

There's Something About Mary
There's Something About Mary

Bread and Tulips
Bread and Tulips

Honeymoon
Honeymoon

Annie Hall
Annie Hall

Life Is Beautiful
Life Is Beautiful

The Philadelphia Story
The Philadelphia Story

Hot Summer
Hot Summer

Mr. & Mrs. Smith
Mr. & Mrs. Smith

Bringing Up Baby
Bringing Up Baby

Gremlins 2: The New Batch
Gremlins 2: The New Batch

The Student Prince
The Student Prince

Midnight Madness
Midnight Madness