English: what is a “thing”?

Tutoring English, new ideas surface about literal vs figurative. The tutor mentions one.

People commonly say ideas such as “One thing to remember is that the store closes at 10pm.”

For a few years now I’ve wondered, “Is the fact that the store closes at 10pm, a thing?”

I would have said no, but apparently I’m wrong: Webster’s indeed says that an idea can be a thing. In fact, its first definition for thing is a matter of concern.

Source:

Mish, Frederick C (editor). The Merriam-Webster Dictionary. Springfield: Merriam-Webster, 2004.