I was thinking more or less of the same question. Our intuition of what a particle "is" has a lot to do with how we perceive macroscopic objects. But particles

I was thinking more or less of the same question. Our intuition of what a particle "is" has a lot to do with how we perceive macroscopic objects. But particles are not really the same kind of thing. Or are they? Is their size correlated with their mass? Do particles consists of some "fundamental matter" or are they more like little machines?