I go through major swings of confidence throughout the day. If I get a compliment from someone or some other kind of validation, I'll feel on top of the world, and then some really small disappointment can sink that confidence into almost depression and a feeling of worthlessness. For example, today I submitted an application for a job that had an "optional challenge problem" I ended up solved this morning. I felt amazing and optimistic. Then, when I got out of the shower, looked in the mirror and was reminded about my receding and thinning hairline, I got into a depressive phase that I'm still in. I'm guessing that'll soon change in a split-second at some time later today.