Redge Semplonius's answer to What painful lessons do programmers learn 'after the fact'? - Quora

https://www.quora.com/What-painful-lessons-do-programmers-learn-after-the-fact/answer/Redge-Semplonius

1. Clever code isn't when debugging it.
2. The value of comments increase exponentially over time.
3. There's a library for that already.
4. That's not what the client asked for.
5. Ask the questions before you code.
6. There's an easier and much faster way.
7. Sleep deprivation doesn't work.
8. Sometimes it pays to read the book.
9. It's not always about the money.
10. There is life beyond the Keyboard.