I have been using a health app, MyFitnessPal, to track several aspects of my life - water consumption, foods I eat, general caloric intake, exercise - and it has been a bit of a slap in the face.
I cook daily and have taken nutrition courses; I felt very confident these past few years about my relationship with food and my health. After two weeks of logging most everything in the app, I had to admit I have been misinforming myself.
Example: some days I eat almost nothing until dinnertime, and other days I eat 3+ meals. For reasons unknown to me - probably sheer hubris - I convinced myself it all evened out. Even though I know better. The app allows me no illusions. If I under-consume, it yells at me to eat food. If I over-consume, it gleefully tells me I will stop losing weight. (You might think I am exaggerating its reactions, and perhaps so, yet the font colors incite very specific feelings.)
Tracking what I eat, how much water I drink, and when I exercise has shown me that I was more or less lying to myself before I documented the data. This has proven to be an amazing reality check. Our own brains can, and do, work against us; we talk ourselves in/out of things we know are bad ideas. We are not always as smart as we think we are.
Since I started using the app, I have more energy from eating more regularly, I am sleeping better, and I feel a sense of relief that comes from knowing I am no longer responsible for holding variables in my brain. But the bigger takeaway is that I am now consciously looking for other areas in my life that might also need a similar examination.