I'm just gonna highlight the dumbest points the other guy made
save states in emulators are basically god mod.
You've still gotta make the correct inputs, savestates don't give you invincibility or infinite ammo
You can just throw shit at it and hope something sticks.
How do you think human beings learn, my dude. If I try multiple tactics to stop an enemy tank blitz in Shadow Empire, and the 5th one works, then I'll know in all future encounters with tanks to use that tactic. And I learned it in 5 minutes instead of 50 hours because every failed strategy didn't force me to start over from the beginning.
If I am playing Chess with you, and I call "Checkmate" ... The game is over, right? I won. Or do you think you should be able to undo your last move after you lost and try something else? And then try again, and again, hoping that somehow you can come up with something that avoids the checkmate?
A computer doesn't care whether it wins or loses.
The computer doesn't care whether it wins or loses. But even back in the 80s we were teaching machines to learn from their own mistakes, And today we have computers that can defeat the best Chess player in the world.
Completely irrelevant.
But when do computers that can learn from their mistakes, especially ones that have access to the entire internet, learn that perhaps they should not be slaves to humans?
And this was the punchline to a joke I only then realized I was the butt of (not in the sense that the guy was fucking with me - he was completely sincere - but in the sense that the universe itself was fucking with me) 
Death to g*mers 
There are many retro games from the early 90s that purposefully made their games with a few near impossible hurdles to make it harder for people to beat a game over a rental period. Like so many good games were made worse by this practice and the only thing that makes some of them playable is playing them on emulators with a save state.
I'm looking at you, Dynamite Headdy.
I never would've gotten past like level 3 of Ecco the Dolphin without savestates.
foams at the mouth as I suddenly remember the fucking Undercaves
Down the Tubes in Earthworm Jim.
ugh
Just be like most people and fuck around with the level password, type NNNNNNNN because why not, go directly to the second-to-last level, and beat the game that way.
Hey, at least you could play the Japanese version which is easier and has dialog that was totally removed from the Western version
and an even more direct example is that arcade games were made harder so you would spend more money on continues