I spent a year in Kirkcaldy, Scotland when I was 12-13 and the school had a strong language-learning ethos. You had to choose whether to study French or German, and a third option was to study them both. I studied French for a years and learnt quite a lot, mainly due to the infectious enthusiasm of our intensely Europhile (Scottish) French teacher.
Then we moved down to west London and I learnt much less French from the (less enthusiastic, slightly robotic) (Czech) French teacher in the local high school there.
All in all, by the time I left school, I'd forgotten what little French I had once known. A few years later, I found myself living in Barcelona and I had intrinsic motivation to learn Spanish and Catalan, mainly on my own, in private, mainly in non-academic scenarios.