I've been studying Russian and Polish language for about four years now. It has been a great experience for me. I discovered that not only do I love learning languages, but I seem to be pretty OK at it. During that time, my thoughts on how one should learn a foreign language have been constantly evolving.
In the beginning, I was largely focused on grammar. This was primarily because the class I was taking focused on grammar. This agrees with a general trend in modern American education, which emphasizes understanding the ideas rather than memorizing the facts. In general, this is good thing. Language courses of the past focused on memorizing vocabulary. Now understanding grammar is the main focus.
Also grammar was easily interesting to me in its own right. Its like math with words. My programmer brain liked it. And it was comfortable. I didn't have to go out on a limb and risk personal embarrassment like with speaking.