To check if there was any progression in my drawing skills, I did another 30 minutes drawing of myself. Though the likeness is moderate, the drawing has a lot more spirit than before (see this drawing to compare).
Even so, to my artist’s critical eyes the result is not good enough yet to stop those rigorous and mind-numbing 2-minutes sketches. It’s clear to me I still need plenty of practice. It has been demonstrated, however, that I’m on a path that might lead to success. If I keep doing those brief sketches (preferably even faster than I’m doing now), I can only get better at drawing a portrait.
Once I’m confident enough, I want to draw other people, to expand my range. That should be a lot easier, because most people are very similar and the differences are relatively easy to spot and draw. It is just the one face you’ve got to master and keep mastering.
After all, the self portrait is an ancient honored skill among artists. Its subject is readily available and stands for all people.
That is all.