Eaten a Big Mac recently? No, of course you haven't — and if you're a young person, chances are amazingly high that you've never tasted America's most famous hamburger.

In a recent memo, McDonald's revealed that, in fact, only one in five millennials has even "tried" its signature menu item. As in, 80 percent of young people won't even deign to taste a bite of someone else's, much less buy one of their own.

The chain's takeaway from this is that, in a sea of Shake Shacks and In-N-Outs, its burgers have "gotten less relevant." It momentarily distracted people from this fact with around-the-clock breakfast, but executives have apparently realized multiple interrupted years of flat burger sales may not be a good omen for a burger brand.

CEO Steve Easterbrook — only a year into his post, so yet to be sucked of optimism — says they're fixing their problem by rethinking the chain's "legacy beliefs." Things like stores without burgers and fries, stores that serve all-you-can-eat fries, stores that give drunk people a "walk-through" — almost everything seems to be on the table.

Unfortunately, the odds are sort of stacked against the chain in the burger department: Past failures include the Arch Deluxe, which mixed mayo and mustard into one abominable "Special Sauce"-lite whole; the Angus Third Pound, which got served on a fancy wood board; and a fresh-beef Quarter Pounder, which franchisees groused would be too much work.

As simple as switching to fresh beef and quality toppings on a properly baked bun is, scaling that for the Goliath chain would be an undertaking, so what customers are getting instead so far is a "panel of sensory experts" that theJournal says has spent the past year studying "every burger on the market" and "rating them against McDonald's core burgers on attributes such as caramelization, tenderness and juiciness."

If their findings were anything like Consumer Report's, the chain's got lots of work ahead of it.