[montyf]

That's good, you're not the same person from day to day after all. As we all should know by now the continuity of the Self is mostly an illusion. Most people, however, decide once during their lives that they are, for example, "not a morning person", and never stop to revise their self-perpetuating beliefs. In our endless quests to categorize and label everything in the universe, we end up doing the same things to ourselves and our own self-images are often composed of simplistic and hastily-formed judgments and categorizations. It seems natural that people don't know themselves, an extreme (but common) example being a bodybuilder with body dysmorphia.