Here is another way to justify how humans are “central” in this universe.

Consider the range in size of what is physically relevant in our universe. This range spans about 60 orders of magnitude (10⁶⁰) from the size of the visible universe at about 13.7 billion light years (~10²⁸ cm) all the way down to the Planck length, which is the smallest scale in which notions of size and distance essentially breakdown according to standard theories, at ~10^-33 cm.

As humans, at about 10² cm in size, we happen to exist near the middle of this range. This really is no coincidence, nor is it some kind of trickery with units of measurement.

It can be argued that if humans were any smaller our brains wouldn’t have room to develop their complexity allowing for our intelligence, and if we were any bigger our brains would lose their practical efficiency which depends on the brain’s ability to interact with itself. In fact, this must be true for all intelligent life.

So if you ever happen to feel down about your size relative to the rest of the universe, know that you are much more significant than any other structure in this universe  exactly the way you are. Even David Deutsch once wrote: “The size of the universe is no more depressing than the size of a cow.”

However, it does seem rather peculiar that we humans exist and are making these observations of size at the point in time when the Universe has expanded to its current size, which just so happens to place us in the middle of this size range. Couldn’t this have been any different?

On the other end of things, one may even be willing to pass the size scale set by the Plank length as being mere coincidence, since the fundamental constants which determine its value could have possibly taken on different values themselves making things very different.