Whats a good lesson you learned on the job?

For me:

Sometimes it doesn’t matter how hard you work, your going to get laid off either way.
Just showing up can sometimes make the difference.
Your not paid to be a software developer. Your being paid to be a problem solver.

Keep notes on your work. One its proof of the work you have done and 2 a lot of people forget things, including yourself. It helps you reflect back. Helps with projects that are spaced apart as well.
On three separate occasions over the course of many years, I ran into an issue and searched Stack Overflow for anyone else having the same problem. The approved answer was exactly what I needed, and went to go hit the upvote button, only to realize I can’t upvote it because I was the author of the answer.

I get this like 6 times a year.

Wait. Are you my alt account?