"It would be really great if there was a save and restore function in real life."
This rather solipsist thought has occurred to many people at some point in their life. It might well have occurred to you as well.
In this writeup I have compiled my thoughts on the nature and effects of such a feature.
The save/restore feature would enable you to save your life to some kind of file at any time, and restore from one of these files anytime. When you died, you could restore from a previous save and try again, like in Groundhog Day, but with you in control.
There can be only One
Only one person could make use of such a function. If several people could save and restore, the universe might be caught up in an infinite loop. An example as to how this might happen:
Two runners at a race, both with the ability to save and restore, both want to be first. Both save at the beginning of the race. The one who would come in second would therefore save and restore, and try again, until he would win the race.
But then the other one would do the same, wanting to win the race as well. And when the second person would restore the universe to the beginning of the race, he would also restore the memory of the first person to the state before the race. The first person would therefore not remember that he had restored before. So both would restore the universe to the beginning of the race again and again, into infinity. Because neither of them would remember having restored a million times before.
Multiple Lives
This feature would make it possible to lead several different lives, and switch between them. If you saved at one point in your life, just before making an important decision, you could explore the effect of the different decisions you can make at that point. Perhaps you'd like both lifes, and then switch back and forth between them.
And that is one of the problems. One morning, you might go to work at the wrong place in the wrong reality. You might go schizophrenic.
More Dangers
You might become obsessed with perfection, and relive a short period of time again and again, because you never manage to do something perfectly - a date, for example.
This ability would also make you immortal, in a way. When you died, you could go back to when you were young, and lead a completely different life. However, you'd be limited by the time frame. You could only experience about 100 years at the very most, from your birth to your death due to old age. You might get bored. Hopefully you'd be able to decline restoring when you died.
Still, it would be fun, wouldn't it?