Laundry List

I just don't understand that expression.

"I've got a laundry list of things to do here."

Really?
Let's take a gander at your rudimentary laundry categories:

• Whites.
• Darks.

Two things?
You couldn't have memorized them? Had to write them down at the top of a long piece of paper? And make a big deal about how you had two things to do? Two Whole Things?

Perhaps you need a bigger washer. Metaphorically.