What steep learning curve do you wish you’d climbed sooner?

This is the question asked by John Cook on Twitter. He lists responses from different people:

  • R

  • Version control

  • Linear algebra

  • Advanced math

  • Bayesian statistics

  • Category theory

  • Foreign languages

  • How to not waste time

  • Women

Mine are: quantum mechanics, Python, cooking, the language of philosophy.

What learning curve do you wish you’d climbed sooner? Give reasons and stories if you feel like it. Do you think other people should climb the same curves?