In those days, unless you were very privileged, you had to learn things from a maybe 1 book, maybe a magazine (some matrix printed stapled pages in my province) and, in my case, without having a computer for the first year of learning basic & assembly. I just had a 2nd hand book + those magazines and some old folk telling me I should learn it. When we did get a computer (borrowed), I knew listings by heart which I typed in, changed and explored. It was somehow nicer than instant gratification we have now. I worked out assembly listings in HEX (I did not know what an assembler was or that it existed) on paper in class (school was of course boring af) and typed it in when the borrowed computer was back. Very nice times.
Mexico surely made it harder, but his father was a bigger advantage than any school. And school fanciness does not reliably correlate with the realness of its instructors.