I rarely let it go but then, I've been surrounded by people and creatures more powerful than me for a very long time. I've learned to moderate.
Never had the pleasure. My family name wouldn't be precisely... known, nevermind the women of my family all being Seers-on my mother's side, mind you.
Outside of magical theory, there's something called quantum theory which posits the existence of alternate universes, based on the decisions you make. But that's Muggle science.