The 'itch' usually starts very small and builds over time (maybe years, maybe decades).
In my case, it was a carry-over from my very first 'home computer' from the late 1970s. It started off with trying to run a BASIC program written for one older DOS under CP/M, a slightly newer (early 1980s) operating system. I eventually wrote a GUI front-end for a very comprehensive emulator on Linux of that very first computer of mine.
Along the way I learned about writing interpretive emulators, multi-threading, C programming, GUI and associated event-driven programming, text-to-pixel-display techniques, floppy-disk controllers, hard-drive controllers, text displays with curses, website-building, deep-search on the web for various bits of obsolete information, etc, etc.
Just do little programs for the little thoughts you have running around in your head. One of those, and you won't be able to predict which one, will eventually be the seed for your 'itch'.
