Eventually in my improvement though, it felt like I hit a ceiling. That ceiling was at the mid-master level back when master was easier to get into (it was the top 2% I believe). The problem was that I could not properly macro 3 bases; that is, keep pace with production cycles while being active with my army. Once it got to a certain point in the game, when I had 3 bases humming and was attacking, I would bank thousands inevitably. Even playing for several years, this remained the case.
Just recently though, I think I passed another tipping point. I suddenly can tell that I know how to properly macro 3 bases and more. I now feel in solid control of the game into the late game. The result is a more whole awareness of the game, with the mechanics to actively meet every aspect of it. The most important thing is that I can now maintain production cycles while being as active as possible with my army. What's really cool though, is that there have been other, unexpected benefits. These are things that I did not consciously seek out, they just all the sudden came to me. So for example I now think to look at the minimap, to keep tabs on my army and my vision. I also think to keep tabs on my production cycles, keep tabs on where my rallies and reinforcements are and where they should be, keep tabs on upgrades, base defense, and the timing of further expansions beyond the 3rd. I think my apm has also increased by maybe 20 or so, again without a conscious effort to improve it.
The reason for the change must have a lot to do with improvement through repetition playing the game, but I think it also to do with my confidence in myself. This is something I've been working on over time, and now led by improvements in my job, I have just felt more confident. I think this carried over to Starcraft, and I feel more relaxed when playing, and can focus more on the game.
It's a great change, and it will probably keep me playing Starcraft for a long time to come.