

Along these lines, I have several important memory locations memorized. POKE 53280 and 1 to change the border and background colors. 828 is the cassette buffer, and 49152 the free memory above BASIC ROM. SYS 64738 resets the machine.
I also can recite the powers of 2 up to 65536.
There are so many weird things about GIMP, and it feels like they add more over time. I’ve moved a layer and then tried to draw on it and had nothing happen. Why? Because the layer was created as an array of pixels the size of the image, and when I move it there’s now a dead zone where there’s no pixels in the visible image. It turns out there’s a special command to expand moved layers to fill the image: https://docs.gimp.org/3.0/en/gimp-layer-resize-to-image.html
There are times using it that it feels like a maze to navigate to just get my changes reflected in the document.