Earlier quoted context omitted.
I was able to do that while I was still studying, which mostly involved memorizing a bunch of stuff. The software industry and its endless meetings drain my energy way more
Are there any other pieces of software you want to write? Depending on your financial situation, see if you can quit or take off your job for a year and write it. The years aren't going to come back to you, and you don't want to die having pushed off your dream until it was too late...
Unfortunately my country has infamously low salaries while having a relatively high cost of living. I have some savings, but I would burn them at a pretty fast rate if I quit my job. My best chance at having another "miracle year" is getting fired, which would immediately provide me with some more liquid cash plus monthly unemployment benefits for a while. At that point I could move to one of the cheaper areas and be financially independent for years.