Deep Thoughts ... or Something

At Reddit there's a quickly growing thread (started September 10) of people stating the "most mind-blowing thing" they can think of. Some top entries:

• We are the universe experiencing itself. [There are a lot along this line -- I've included just a few.]
• No one is going to remember your memories.
• You are to yourself what your thoughts are, you are to others what your actions are.
• When a photon is emitted from its source, it instantly arrives at its destination from its frame of reference, even if it took it 13 billion years to do so from ours.
• An atom is around 99.9999% empty space, making everything in the universe mostly nothing.
• One billion seconds is 32 years. One trillion seconds is 32,000 years. The difference between billion and trillion is equivalent to the difference between your lifetime and the entirety of human history.
• As you look farther away, you are looking farther into the past.
• There's an ocean of magma right under you.
• The time difference between when Stegosaurus lived and Tyrannosaurus rex lived is greater than the time difference between Tyrannosaurus rex and now.
• How life is like Tetris: your errors pile up but your accomplishments disappear.
• At some point, for a very small time, out of billions of people on Earth, you were the youngest one
• Given enough time, hydrogen starts to wonder where it came from, and where it is going.
• In a human, there are more than 125 trillion synapses just in the cerebral cortex alone, which is roughly equal to the number of stars in 1,500 Milky Way galaxies.
• Cleopatra lived closer in time to the first Moon landing than to the building of the Great Pyramid.
• Pi is an infinite, nonrepeating decimal - meaning that every possible number combination exists somewhere in pi.
• Currently you're oldest you've ever been and youngest you ever will be again.
• They put people on the moon with far less processing power than the phone in my pocket.
• The brain named itself.
• Every human came from an orgasm.
• There are more atoms in a grain of sand than grains of sand on earth.
• [F]or 3.8 billion years, a period of time older than the Earth's mountains and rivers and oceans, every one of your forebears on both sides has been attractive enough to find a mate, healthy enough to reproduce, and sufficiently blessed by fate and circumstances to live long enough to do so. ― Bill Bryson, A Short History of Nearly Everything

Some of these are trite, a few questionable, but all interesting.  There's at least a half dozen I could add.