I remember some from my schooldays, but my French isn't great. I lived in France for a while, but I didn't have a lot of contact with French people because of my inlaws. So I didn't learn much French while living there either. But I did start to learn vocubularies and continued that when I moved back to Holland.
Then one day, I met a French lady living in Holland, that's when my French improved, because we talked a lot in French. When you talk French very often with someone, that's when you really learn the language. I could improve the French I had mostly known from books and the few sentences and words I had learnt while living in France.
You can't learn a language only from books, it's important to regularly talk in that language with someone who speaks it very well. My French is much better now, but I do have an accent and many grammar mistakes, I haven't really spoken it for a long time now, so I guess it's worse now than it was some years ago.
Another example, I've tried to learn Russian, but it's difficult. Pronounciation is difficult. Grammar is terrible. I don't have anyone to talk to in Russian, so I can't learn it better. I became intrigued by Russian culture when I was about 18. I also liked the way the language was written and wanted to learn to read and write it. And there are many great Russian books which would be nice to be able to be read in their own language. So over the years I've made some attempts to learn it. I can read some words and sentences, but that's about it.
While trying to learn Russian, there was nobody I could talk to in that language regularly, so I didn't learn it very well.
While trying to learn French, I had someone I talked to in French regularly, so I learnt that language much better.
Conclusion: learn from books, but most important, there should be someone who speaks that language with you very often if you really want to learn the language.