“Simple Car Stuff”: 52 Skills That Require Minimal Training But Give Maximum Results

Learning where your water main shutoff valve is for your house.

Learning the shortcuts for software you use daily. I basically force the juniors to start using shortcuts it always pays off in the end (software engineer). But this goes for everyone, designers in Photoshop, people using spreadsheets, if you use it daily, put in a bit of time to learn how to be efficient.

Microsoft Excel. If you know basic math and calculating then you can do amazing things.

I'd say spending 10 hours learning how your computer works will pay off forever. So many people are unaware how their machines work.

Learn how to swim. It can save your life. It shocks me how many people accidentally fall into water and drown because they don't know how to swim. You can easily learn the basics and enough to keep yours