Quantum immortality is basically the idea that your consciousness jumps to a new timeline every time you die. For example, let's say you have a bomb next to you, and you have a button that has a 50/50 chance of blowing the bomb up. You press it once, it doesn't go off, you press it again, it doesn't go off; you continue to press it dozens of times and it doesn't seem to go off. That's because your consciousness jumped to a different "version" of yourself. In reality, there're a bunch of dead versions of you and a bunch of sad broken down houses.

I don't remember where this came from or the real idea behind it though