A friend of mine showed me a link to a deviation that was a comparison of an old drawing and a new drawing, with the same subject.

In that case, a year and a half made a world of difference. Even the first drawing was, in my opinion, beyond my capabilities, to say nothing of the second.

I see no such improvement in my own work, even over a longer period of time. It's things like these that make me wonder if I'm putting enough time and energy into this...