Motion Graphic Theme

As I would like my motion graphic to be based around a 3D environment, I would like my theme to be something that I could easily implement in one. The things I am focusing on mostly is that my animation will flow nicely, with no abrupt pauses, and that the graphic will spread throughout the environment that will be working in. Thinking about it this way, a theme that could work would be water, or something, flowing throughout the environment, or the spreading of a bacteria or disease, and how it will effect the environment.

However, in the case of using something like the latter idea, I will try to exaggerate it as best as I can, to make something that isn't realistic, but retains the same idea. For this I could shift my research into a more medicinal area, and study the movements and patterns from medical videos, and implement this into my motion graphic. I would stick with making it realistic, but I would like my motion graphic to be able to appeal to most people, not just people who are interested in medicine, and to do this I will back away from the realistic aspect of it.

That being said, I may drift from this idea if anything else comes to mind, but at least I have the basic idea as to what sort of things I want my motion graphic to feature.