I started learning Spanish when I was about 10 years old. I only learned a little, but because I learned at that age, I believe it allowed me to roll my r's, which I can still do to this day. But then some time when by, and I didn't study or practice. It was hard. There was no one to practice with. Then I took Spanish for 4 years in high school. I"m sure I learned a lot of grammar, but it was merely a task to complete, and I was mostly learning Spanish in high school so that I wouldn't have to take it in college. This is a terrible reason to learn something. So, I probably didn't really learn much.
I went to Mexico when I was 22, and in preparing for this trip I studied with a friend and learned some words and phrases. Then when I was 24 I decided to go to Ecuador. I again learned some language skills in preparation, and I learned a whole lot while I was there. But then I came back and didn't have anyone to practice with and years when by without using the language. Sure, I listened to podcasts and tried to read textbooks and children's books, but it was boring and I would only hold up for a few months. Still, I'm glad that I did it as I believe it kept the information "fresher" in my mind.
A few months ago I meet a language partner on a language exchange, and we meet several times a week. My spanish skills really blossomed during this time. But, alas, my partner stopped being able to meet and now weeks are going by and I'm not using my language skills, again.