If we look at something, it appears physical, made out of some stuff.
The stuff of course is made of molecules, combination of atoms which bind together by exchanging electrons or by electrostatic forces.
The atoms, made of electrons, protons, and neutrons. There are fundamental particles, the electrons, and composite particles, protons and neutrons, which are made up of quarks, conservative particles that are never seen naked and free.
These particles, if we try to observe them closely we find that we can not determine both their exact velocity and location simultaneously. This is because particles have a dual nature, they also have a wave-like nature and it is that wave-like nature that makes it impossible to determine exactly where a particle is and know it’s velocity simultaneously. We can only get probabilities of where it is likely to be, the wave seems to be a sort of probability wave.
And that wave isn’t really physical stuff, it’s a perturbation in some sort of field. And what exactly is a field? Well, it seems to involve some kind of force but no actual substance.
So here we are, the substance of our being really quite an illusion, or at least our physicality in the way we normally think of it. Instead we’re some kind of complex waves in a number of fields, that somehow is able to think, comprehend, even create.
Personally, I think we are all just God thought, and if God stops thinking about us, forgets us, we cease to exist. Fortunately, God doesn’t suffer from ADHD or we’d all be toast.