Much of what we view as reality is based on our "common sense" which, in turn, is based on our perceptions of our environment. This is problematic, since our perceptions are so limited (Ref. 1).
In particular, we cannot intuitively understand Space at either the micro (e.g., molecular, atomic, subatomic/quantum) or macro (e.g., interstellar, intergalactic) levels. When things get small enough, for example, particles of matter end up being only energy waves and, in fact, matter pops in an out of existence, being created from and disappearing into nothing. At the macro level we aren’t capable of truly understanding distances such as the span of our galaxy (approximately 100,000 light years), where a light year is 6 trillion miles -- the distance light, travelling at 186,000 miles per second, traverses over the course of an entire year. Similar observations can be made about Time.
Common sense also tells us that Matter and Energy are different. In reality, they aren’t.
We can assign numbers to all of this but we can't truly understand it at the intuitive level. This is why modern physics and its associated mathematics frequently describes Physical Reality so well despite the fact that the conclusions reached can be so counter-intuitive as to seem impossible.
References:
1. "The View from the Center of the Universe: Discovering Our Extraordinary Place in the Cosmos" by Joel R. Primack and Nancy Ellen Abrams