List of things that blow my mind

This is a list of various concepts and ideas that I find so profound they blow my mind. Not all of these concepts are complete, but most of them appear to be

Concept	Description
Cutting a moebius strip	Cutting a paper moebius strip creates very unusual results compared to a simple paper ring.
Deep time	The universe is around 13.8 billion years old, and the Earth is around 4.5 billion years old. In that time, a huge amount of changes have occurred.
Determinism	Freewill is an illusion, our choices and even our very thoughts are determined by existing events entirely outside of our control, and proving freewill would require time travel.
Emergence	Complex and unpredictable properties emerge out even the most basic rules. For example, a cellular automaton.
Euler's identity	e^(i * π) + 1 = 0. Several unrelated mathematical constants, two of which are transcendental, arranged in a specific order in an equation, equal zero.
Evolution	If mutation exists in reproduction, a population will evolve over time in complex unpredictable ways, especially if natural pressures are placed on the population.
Field of vision demonstration	Our eyes actually only focus on a very tiny region, while our brain infers everything else we see.
Genetics	The recipe for life is so unbelievably convoluted that minor changes in one gene can cause major changes in seemingly unrelated areas. For example, the domesticated fox experiment.
Microscopic and Macroscopic worlds	Entire structures exist and thrive both at levels much smaller than we can see, and much larger than we can fathom. For example, gut flora and the large scale structure.
Natural selection	Organisms capable of evolution, when in an environment with limited resources, will evolve to better utilize those resources.
Naturalism	The supernatural and spiritual do not exist. Everything in the universe behaves according to natural laws including the complexities of life, the strangeness of the universe, and depth of mathematics and logic.
Programmatic recursion	A simple function can call itself to create complex results. For example, Sierpinski triangle.
Distance equals time	Because light has a maximum speed, as you look at things further away, you're also seeing things as they existed in the past. The sun is 8 minutes behind, the Proxima Centauri is four years behind, Andromeda is 2,500,000 years behind, etc.
Size of the universe	The observable universe is about 93 billion light-years wide and, inside it, there are an estimated 200 sextillion stars.
Spacetime	The fact that space and time are a single inseparable thing.
Symbiogenesis	Some biological organisms evolved from initially separate organisms that developed a symbiotic relationship so compatible as to become one organism. For example, mitochondria and the Portuguese man o' war.
Wave–particle duality	At the quantum level, matter behaves both like a wave and particle depending on whether it interacts with other matter. For example, the double-slit experiment.