I learned French in a way with many similarities: I took a semester of engineering courses at a French uni.

Like the author notes, the trick seemed to be (1) you are interested in the exact meaning of the words and phrases (2) finding many `hooks` for memorizing. In my case, it was specific problem sets, personalities of profs, ... (3) rhythm and structure. For him it was the structure of web sites. For me, it was class schedule.

I did about zero language specific training that semester. Got good grades, even by French standards. I did have a scare half way into the semester by doing poorly on half my midterms, but pulled it through by the end.

I did have a foundation of high school language courses, but I was about as poor of a language student as you can imagine.