The most important muscle to build is discipline.

As a teacher, it is easy to tell somebody else that improvement comes from practice. Keep turning up. Do the difficult thing again. Accept that progress is usually accumulated rather than sudden.

So I started keeping score — not of appearance, but of work. Seeing one of my students consistently turn up and put the effort in further inspired me to keep doing the same myself. The number above is simply the accumulation of those ordinary decisions — one block of 300 at a time.