As an extreme but interesting case, I know someone who has had a majority of his endocrine system surgically removed and now relies on self-treatment of hormone

As an extreme but interesting case, I know someone who has had a majority of his endocrine system surgically removed and now relies on self-treatment of hormones. He has had in the past extensive excel sheets tracking his dosages alongside behavior, appetite, energy, etc. It's utterly amazing the amount of correlation he could derive between various hormone levels once he was made directly aware of them. Similar kinds of information about day-to-day blood chemistry might be available through retail-available blood testing. This is QS all over again, but with a significantly more powerful bite—blood chemistry is a quantitatively powerful look into your body's current state. It's a human debugger.