If you could invent anything, what would it be?

OK we aren’t talking reality here. No concerns about physics, practicality, or unintended consequences. This is purely for fun folks.

I am thinking about eyelid props that would hold them open moisten the eyes with drops.

Also a house that would shut down once a day flip upside down and cleanse itself. No idea why it needs to flip upside down other then that is how I imagine it.