I was explained to really early on that "mystical energy crap" is a visualization tool. You can think about how you should control breathing and contract muscle

I was explained to really early on that "mystical energy crap" is a visualization tool. You can think about how you should control breathing and contract muscles in a sequence while balancing OR you could imagine being rooted to the ground and channeling "energy" from your grounded foot through belly onwards to the arm and fist "through" the target you are aiming at (just one example). It's all for practical purposes, see it only as a tool (unless you're into Kempo+Zen). It's all based on hard cold facts - for example it's easier to bear the load, punch something or absorb an impact while exhaling rather than inhaling.