OK, then -- What might one learn by tracking something as squishy and undefined as happiness? I find it ridiculous that anyone would attempt to reduce happiness to a single numeric range.

  - I don't need to track my happiness to know if I'm happy. 
  - I don't need to track my sleeping patterns to learn how to sleep better.
  - I don't need to track every calorie to know if I'm eating well.
  - I don't need a computer to tell me if I'm healthy.

It seems to me that QS is just a new fad that will make a certain personality type feel like they have control over their lives.

"Quantified Self -- Using numbers, technology, and science to divine common sense!"