The highest standard is useless if it appears only on your best days.

A standard that only appears when you feel good is not really a standard, it is a description of your best mood. What people encounter is the average, and if the average is well below what you are capable of, the high standard exists mainly in your own idea of yourself. The measure is what happens on ordinary days.

Look at your last five pieces of work rather than your best one. That set is the honest picture. Then ask what would raise the weakest of the five, since that is where the real improvement lies.