If anything is certain, it is that change is certain. The world we are planning for today will not exist in this form tomorrow.
It is not possible to know what you need to learn.
Very few of the great leaders ever get through their careers without failing, sometimes dramatically.
Quality means conformance to requirements, not elegance.
In a true zero-defects approach, there are no unimportant items.
Most things don't work like they are supposed to work.