What is the one thing that should be taught in school that isn’t already?

Safe sex, how to do taxes, how to change a tire and check oil, how to speak and be kind to people who aren't like you.

Common sense??

[u]Lots of 'HOW TO's ![/u]

Wallpaper a wall.
Paint effectively.
Lay carpet/flooring.
Basic Plumbing.-unblocking a sink trap/toilet etc.
Effective budgeting. How to tell a bargain from a fix !
Money management. including Taxation/Planning for upcoming costs/saving.
Prioritizing.
Basic childcare.
Meal planning/preparation.
Basic 'you and the law'.
Apply for grants and unemployment etc.
Coping strategies for grief and loss.
Basic motor vehicle maintanance.
What to do in the event of a death.

Actual life skills like paying bills, taxes, emergency first aid

Meditation

Money management and death, loss and grieving. And philosophy. There are lots of folks with no guidance system careening through life like a pinball. No real goal. Just bouncing around.

Bank stuff

taxes

Intrest rates/bank loads sliding and fixed. How each level of government works. Etc etc.. Oh and liberalism is a mental disorder 😃👍

How not to be a complete fucking asshole.

How t fight depression once you r heart broken

Actual goddamn art.

How to balance a check book

Yoga and meditation.

Survival :)

Seeing from the answers, it seems like a lot of people here are uneducated. You should have paid attention in class!

Handwriting and learning analog time

Parenting skills should be mandatory.

Karate!!!

🤷