My brother is a math teacher (retired), who loves numbers and always has. He and I and others in the family have an ongoing, never-ending, heavily-CC'd email conversation about everything in the universe, and an old friend of both me and my brother is always included in the emails, since he's been part of the living room for fifty years and he's basically family.

Yesterday my brother, Mr Math, emails, "This Sunday celebrate Pi-day."

Because it's 3.14. It's a very stale joke he's been telling every March since he was 8 years old.

I reply, "I don't even know what pi is. I know the number to a few digits, and it's math and geometry and all the smart people and science fiction agree that it's important, but I never saw the point and it never sunk into my head."

Now, this is actually a calculated reply, and not quite true. I do know what pi is, vaguely, but mostly I know that my brother will explain pi to me again, and he loves doing that. And also, our friend who's included in the CC's flunked high school algebra long long ago, so my comment will make him feel good.

And it works. Our friend says, "The same with me Doug, the same here. I like a good apple🍎or cherry🍒Pi 🍽 myself!!" And my brother explains pi, so he feels like a math teacher again. Everybody's happy.

For anyone who needs it or wants it, here's my brother the math teacher, explaining pi:

Pi is really very simple in a complex way. Everyone knows that all circles have one thing in common. Their symmetry. The (string) distance around can be likened to the (transverse) distance through a circle. The complex relationship is that there’s some (fixed) relationship for 3 in, 6 in, 12 in, etc. circles. The around distance (circumference) something of the same in ALL circles as relates to the across distance (diameter).
Well, the beauty of a circle is that around is like across in some way. The Greeks thoughts were that circles represented perfection. The Egyptians and Mayans knew this too.
The truth of the matter is that C = π X D.
Yes, π is roughly 3.14159265373 and so forth, but it’s really the simple aesthetic beauty. Maybe the number isn’t simple. The truth is.

Thanks, bro. Sometimes I don't quite understand you, but I love you. I still don't give a hoot about pi and barely understand it, but two people I care about got a smile, and so did I.