system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If energy can't be neither created nor destroyed. How did it came into existence?
gpt
No idea... and it's a big open question. Answers are all some version of kicking the can... 

*Cyclic (It's always been!)

*Cyclic Ecpyrotic (It's always been, because of higher dimensions interacting!)

*Eternal inflation (Ceases to be a meaningful question, "it's always been!")

*The universe is a simulation (God did it!)

The thing is though, conservation of energy isn't a law that applies to whole universes, it's part of a set of constants that is a feature of the universe we live in. Conservation of energy doesn't mean much, if anything, when you're talking about the entire system, from the outside.