If I ever retire, I'll probably be inventing a little more. I love tinkering with technology, whether it is hardware or software, or a combination of both. It could be something that needed 3D printing in order to fix some consumer device that had a missing part, or maybe the four wheeled robot with omniwheels that is still sitting in my workshop.
But somehow I am still also intrigued by so-called free energy devices, because there is this intuition in my mind that they should work, even though I have never seen a working one live. But then again I have never seen an alien or God either, but I don't doubt the Grand Overall Design exists.