> Your limbic system is very very complex and is naturally in a state of working. No human intervention.

It has evolved over millions of years. The evolution included billions of variants that didn't work and died before being able to reproduce.

And even then, are you saying everyone's brain is perfect and never needs any external intervention?

On top of that, we have to continually tend to our bodies, feed them fuel (sometimes at risk of life and limb), exercise them, clean them, tend to them, visit the doctor, take medicine/drugs, etc., just to keep them in good shape. And they eventually have a 100% failure rate.