I don’t know if I would say they’ve “left the planet” in low earth orbit. They went to space, but they’re still very much gravitationally bound to earth. If their orbital velocity were to suddenly become zero, they would fall to earth very quickly. The people who went to the moon left the planet.

But to answer your question, the fact that we harnessed electricity to create a communications network that can nearly instantly communicate from anywhere on earth to anywhere else, still amazes me.

Agriculture is nuts. Put food in the ground, and get more food back later? Cool!

Food preservation is incredible too. A single fish rots pretty fast when it dies, but we figured out a few dozen different ways to eat that fish years after it croaked. In serving sized portions, no less.

apparently our ability to throw things somewhat accurately is impressive

Healing is pretty neat.

Childbirth. Just the physical volumes involved are impressive, especially with that dummy big head that has to flatten out, but there's also calculations showing that in the later stages, the mother is actually using energy at the fastest possible rate the human body can sustain for more than a short burst.

On that note, eating. You can just take in certain random things from the environment, and your body can rearrange it partially into more body and partially into energy. No artificial machine I'm aware of can do that.

Living outside of water. Life is a water thing, it started in water and cells are mostly made of water. We can just kind of bring our own supply, and that's crazy. In a lot of ways your house is more like outer space than the place where we started off, and indeed the human body can tolerate a total vacuum for a bit without damage.

My favourite is language, not even writing, but language itself. We could collectively invent ways to understand each others with codes shared by tens of millions of individuals, living kilometres apart.

And then I also love early astronomy, like being able to approximate Earth's circumference (or later the time needed to reach Asia by navigating west), based on the shadow lenght at two fairly distant (but still pretty close) places, thanks to that quirky thing some friends of yours invented to divide land called geometry. To say nothing of those demonstrating Earth rotates around the Sun just by looking at star positions during the year.

As for recent things, something pretty cool we take for granted is radio signals. Information getting places without anything moving, just invisible vibrations through space.

Almost everything.

So much is taken for granted, taking it away is the only way to appreciate it.

One example: refrigeration.....so powerful, but so mundane... until it's gone.

Who can blame them though?

Basically our entire daily life would have been absolutely unthinkable for 99.9% of human history. Light and hot showers whenever we want them. Instant communication with the other side of the planet. Thinking machines with the entirety of Human knowledge in our pockets.

Literally our metabolic system. You eat materials like minerals that are dead and your body absorbs them and turns those into a part of you.

I always think about the Chunnel, how easy it is to travel between London and Paris when before it would have been boats.

Harnessing the power of electricity. How in the world do you look at lightning and think: I want have that

Just being "alive." We become alive, some sort of "spark of life" pulses through us, and at some point, that "spark" leaves us, and we are nothing more than a rock. What is that "spark?"

Everything is either animate of inanimate, so how did things become animate? At some point, something had to get that "spark," and become alive, then spread that life around. How did/does that happen?

Is this "spark" unique to Earth, or is is possible to exist elsewhere? Did some nearly impossible combination of factors all happen to line up and cause "life" to emerge, like a room full of monkeys randomly typing Hamlet, or do those factors exist in other places?

Of course, many people would assign a religious explanation to that "spark," our Soul or whatever, but that's just making up a silly story to explain something we don't understand.

walking. take a moment to think about it.

literally this. where are you from? chances are i live in the other side of the planet, but here we are. hi!

Walking upright. Being able to walk all day.

How fast we went from first flight to space flight, on the scale of human existence it was in the blink of an eye, but from our daily perspective, it feels like such a gigantic feat

Penicillin / antibiotics comes to mind. As well as vaccines. "Oh you're body is being taken over by millions of microscopic organisms? Take this pill and it will go away. Maybe take this shot too so it won't happen in the first place."

And of course computers + the internet were a pretty big boom too.

The fact the internet actually works at all is nuts.

i travel constantly, and every time I'm flying in a plane i am re-amazed.

i think about how easy and quick it is to fly anywhere in the world and I'm sitting in a bit metal tube floating in the air.

it's bananas.