Topological Limericks

A mathematician confided
That the Möbius strip is one-sided
And you’ll get quite a laugh
If you cut one in half
For it stays in one piece, undivided!

A mathematician named Klein
Found the Möbius Loop quite divine
Said he, “If you glue
The edges of two
You get a weird bottle like mine!”

The topological part of my brain
Finds Möbius strips quite a strain
But I make you this pledge:
I’ll glue one at its edge
And build a real projective plane

Any more? (Or can anyone give me attributions for the Anons?)