The mat is the objective (or at least distinct from your own personal judgement) measure of your goal. If your goal is important to you, an objective measure of your progress towards it is more valuable than your own flawed and biased opinion.
The mat for the diary might be the times you consulted back to it for useful introspection and came out better for it, the mat for your health goal could be your blood test from the doctor, etc.
The point is that the mat doesn't care what you think of yourself. I would ask you: when you judged your progress from yesterday, was it with a mat - a brutally objective test - or was it with something less honest?
Whatever your goals are, if you really, truly care about them, and you understand what your true objective is, you'll value the mat. The mat is not about what other people think, it is about undeniably simple and real feedback on your objective.
The mat for the diary might be the times you consulted back to it for useful introspection and came out better for it, the mat for your health goal could be your blood test from the doctor, etc.
The point is that the mat doesn't care what you think of yourself. I would ask you: when you judged your progress from yesterday, was it with a mat - a brutally objective test - or was it with something less honest?
Whatever your goals are, if you really, truly care about them, and you understand what your true objective is, you'll value the mat. The mat is not about what other people think, it is about undeniably simple and real feedback on your objective.