I was making a minnow net to catch baitfish for my son. To make a cone you need a half circle of material out of mesh.

Now in a 2D world the where there is no thickness this would be correct, if material can be added to fill gaps.

In a 3D world, any round object with a hole and some thickness could be a straw. A washer is a straw by this logic

At step 4 it is not a straw anymore..

Wait this is only one hole?

If a flat disc has no holes, how many holes does the surface of a sphere have?

laughs in klein bottle

It still has two holes compared to a sphere, and that is our usual frame of reference.

I like eating

There is a great sauce video about this: https://youtu.be/egEraZP9yXQ