I took three years of Spanish and got an A every semester. Even when it was still fresh in my mind, I was nowhere near able to hold even a very simple conversation. And now just a few years later it's all totally gone from my brain.
My mother's native language is Spanish and she never taught me, which I resent her for. But I still find it incredible how shitty my public school education in Spanish was. We really should be teaching kids a second language from kindergarten up.
The only way to learn a foreign language is through a lot practice and exposure. This is not something that language classes in school can provide unfortunately.
Try reading some children's books in Spanish and you'll learn more Spanish than you ever did in school.