Particle or quantum physics is just too complicated for the average person to completely understand. It never stops. Every day a new and smaller particle is discovered. The action and interaction of particles and anti particles fills volumes of literature. Only the most learned can understand.
Concepts play a key role in our understanding of the universe.
The process of learning is really a process of exchanging old concepts for new. For instance, the concept of space being empty and nothing. This must be replaced by a another concept of space being a something. The universe is filled with an invisible fabric. It is not a something as can be explained as a rock or a tree because it is not composed of matter.