“Two all-beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame bun.” If you were around when this commercial came out in 1984, that description of the McDonald’s Big Mac just rolls off the tongue. My wife hasn’t had a Big Mac sandwich in years yet she still remembers the jingle (first created in 1975) word for word. Not so, the kids of today.

In a corporate memo obtained by Julie Jargon of the Wall Street Journal, McDonald’s executives not only worry that the iconic sandwich “has gotten less relevant,” but also mention this startling statistic: Only one in five millennials has tasted a Big Mac.