Saw this yesterday on Facebook:
- Optimists see the glass as half full
- Pessimists see the glass as half empty
- Engineers see a glass that is 50% too large

... suggesting an addendum:
- Optimists see the glass as half full
- Pessimists see the glass as half empty
- Engineers see a glass that is 50% too large
- Awakened ones put the measuring cup aside and learn to appreciate whatever life serves