One day when I cooking my pasta as usual, the water boiled over, so I stopped the heat, and then forgot about it and left it like that. But the noodles cooked through.

Since you turn off the heat during the cooking process, it's easy to forget how long your pasta's been in the water, so don't forget to check the timer.
Depending on the type of food you're cooking, you sometimes have to wrap the pot with a towel when you're trying to take advantage of residual heat, but that's not really necessary here!

Carbonara Made with Milk and a Whole Egg. Recipe by Popotankobu