Alka-Seltzer's 'I Can't Believe I Ate The Whole Thing:' A True Story

By Jacob Shelton

Actor and comedian Milt Moss. Source: (Miles Laboratories)

Certain TV commercial catchphrases from the 1970s stand out as landmarks, as famous as any movie quote. Alka-Seltzer's "I can't believe I ate the whole thing," from 1972, is at the top of that list (along with other gems like Life Cereal's "Mikey Likes It" and Tootsie Pop's "How Many Licks?"). 

What is it about a catchphrase that speaks to us? How can some advertisements fall so flat when others find their way into our collective craws and stick there forever? Writing a good commercial tagline is akin to writing poetry, though for the most part these turns of phrase go right over the viewers' heads. But when something’s in the sweet spot it goes from being another piece of advertising to a cultural phenomenon.

It's remarkable to think that Alka-Seltzer's "I can't believe I ate the whole thing" might not even be the best-known tagline for the product from the 1970s. Two years later, another line -- this one more of a jingle -- wormed its way into our consciousness with its maddening simplicity:

"Plop plop, fizz fizz, oh what a relief it is."

But that's a story for another day. Read on for the inside scoop on "I can't believe I ate the whole thing," the advertising tagline that became so much more.