In my opinion the human experience would be a lot more pleasant if we were taught at an early age some very simple things:

1. We are each, solely responsible for our own mental state. This is true at all times.
2. Mental health is just like physical health, it is something we need to take charge of and work on continuously.
3. Happiness is something we need to create for ourselves and it needs to come from within ourselves.
4. Helping other people without it being asked or expecting a return is the only external path to true happiness. Everyone should pursue this path, always.

If we devoted the first five years of people’s education to really learning those things, teaching them the tools to seek happiness before teaching them academics, well, that would be something truly wonderful.  In my opinion.