Making an honest mistake is acceptable. Failing to fix it is not.
Greatness is not how you feel, it's how you make others feel.
It's fine to wait for an appropriate time, but it's inappropriate to wait forever.
Your profits reflect the success of your customers.
Listen to customers and you will hear them. Look carefully at customers and you will see them. Do both and you will understand them.
Enjoy your work so that others may enjoy the results.