I learned French a year ago, when my family moved to Quebec and knowing French became essential to integrating and making friends at my new school. It wasn't a choice; French was something I had to learn if I wanted to do anything.
I suppose it was exciting because I was learning so incredibly fast, thanks to being totally immersed in the language. Everyday, I was getting better and better. As I got better, more opportunities opened to me.
Now that I've moved to English-speaking area, I've totally ignored my French. I think if I went to Quebec for a week, I would pick it back up real fast; but now, I simply have no reason to speak French.
My best advice to you. If you want to learn a language quickly and have fun while doing so, move to somewhere that they speak the language or, at the very least, go on a vacation there.