[simias]

It's perhaps not as life-changing as some of the sibling replies but one thing that has really amazed me over the past few decades is how much lighting has progressed.

When I was a kid in the 90's I already enjoyed electricity and electronics and I would play with those low power incandescent lightbulbs powered by 9V batteries. They would generate a lot of heat and very little light, to the point that it wasn't easy to tell if it was on when the sun was bright.

With a modern LED and the same setup you could generate enough light to blind yourself.

[mrguyorama]

I like to point this out in relation to Star Trek. In TNG, they had tablet computers, replicators, teleportation, voice command, all these things that we consider future magic or current awesome technology. And then an away team goes down to the surface and pulls out a flashlight using an incandescent bulb that can barely be seen.

LEDs are genuinely revolutionary in a way everyone just kind of overlooks.