I posted awhile ago about an interactive animation that allows you to use a slider to visually travel through the spectrum of scale that encompasses the Universe- from the quantum level to the most expansive areas of the cosmos.
The Scale of the Universe has been recently updated with more info & animated graphics.
This is one of the most mind-blowing conceptual tools I've come across on the web.
Unfortunately, even presented in such a simple & accessible format, the vast nature of reality is ultimately impossible for the mind to fully grasp.
I think that studying fractal geometry, and especially how it applies to generative computer art, has helped me develop a better understanding of the Universe. The natural world is full of recursive patterns & self-similarity on all scales.