Wizard of Oz

1. We know what we don't know by realizing the spaces or gaps in our intelligence when faced with a new situation.
When we realize that we do not know everything then we know what we do not know.

2. Once what we do not know is discovered then we can learn that.

3. If what we accomplish is lower in value than a particular act that we perform then the omission becomes more significant than the act.

4. We know how good our lenses are through "hindsight".