Theists: "How do you get something from nothing?" Physicists: "There was never nothing."

It's worth noting that any special allegation that is used to support the alleged existence of a creator and/or maintainer of the universe, separated from the universe itself, can be reused towards the universe itself.

• "nothing is eternal" - then your god isn't eternal.
• "actually, God is an exception" - then the exception is the universe itself.
• "the universe must have a cause" - then your god must have a cause.

And once you do it, the new hypothesis abides better to the principle of parsimony, because you're removing some junk deus ex nihilo entity and assigning its attributes to an entity that you know to exist.

The Neverending Story solved this in 1979. Using your imagination, you create something from nothing. And because imagination is not real, that something is not real. If something is not real, then nothing is real. If nothing is real, then nothing is something. So nothing will always be something. Bob will always be your uncle. /s

"We smash two very small things together and somehow a buncha new things result from the explosion."

Human beings only think in terms of all things having a beginning because in our limited frame of reference everything we know always has.