Our latest understanding of gravity is based on Einstein's general theory of relativity which says gravity is geometry not a force and matter curves the space around it. So why it is hard to find or believe that elementary particles can also do so. If they can't do so, why can't it be just that a system of particles curves space. And I know that gravity is considered as one of the four fundamental forces. And why it is a force while it is just a consequence of the curvature of space and it does not show any push-pull mechanism just like Newtonian gravity, which is quite convincing to think gravity as a force.