Ask HN: Autodidacts, what's the most useful* thing you've taught yourself?

[shovel]

* feel free to substitute <useful> for interesting/ difficult/ practical/ powerful/ impressive/ your own adjective.

[owebmaster]

As a non-english speaker, learn to read and speak english was the one thing that had more impact in my life (professional and personal).

[RaitoBezarius]

Time management techniques (with or without help of web apps, or tools, i.e. Trello, Asana, Toggle, etc…).

[Odenwaelder]

Git.