Imagine seeing several folks with Alzheimer's and for the first time hearing the term. Yet you didn't quite hear it right, and your brain interpreted "Alzheimer's" as "old-timers" instead. It makes sense because you observed most of the folks suffering from the disease are elderly, and the two sound pretty similar.

That's an eggcorn, an idiosyncratic substitution of a word or phrase for a word or words that sound similar or identical in the speaker's dialect. The new phrase introduces a meaning that is different from the original, but plausible in the same context. This is as opposed to a malapropism, where the substitution creates a nonsensical phrase.

Eggcorns typically involve replacing an unfamiliar, obscure or archaic word with a more common or modern word. They are very similar to the form of word play known as the pun. The key distinction is that a pun is intentional whereas an eggcorn is not. The writer or speaker of an eggcorn is unaware of the mistake, using his or her imagination to resolve something heard to something that makes sense.

They say you gave him the peanuts.
That's based on antidotal evidence.

Was he really dead for 30 seconds?
No, he was just unconscientious.

Well, he blames you.
I will not be made an escape goat.

<But it was your fault.
No, there are migrating facts.

His throat still hurts.
Poor baby should have his sarcophagus checked.

<At least you drove him to the hospital.
He should be internally grateful.

His knee hurts as well.
Oh, he wore out his knee cartridge years ago.