Speaking as a self-taught coder, I have to agree with you. You have to be able to focus.

BTW, we used to call the process of getting an entire problem into your head 'chunking'. If you are interrupted at *all* it goes 'poof!'. So be sure to find a place where you won't be interrupted - and beware self interruption.

Speaking as something of a dinosaur, I was very lucky: things were very simple when I started. If you want to check out what it was like, there's an online simulator at https://schweigi.github.io/assembler-simulator/index.html

I found that having a good handle on what the CPU was doing, how addresses and stack framing (and so scoping and recursion) worked a very useful 'base' for learning everything else. Maybe it'll help you, too?