There are two distinct activities:
- Linguistics. This means language science. It is the conscious study of the components of a language or language in general. This is like all other sciences and intellectual persuits: biology, chemistry, mathematics, etc..
- Language learning, or rather, language aquisition (which is the term I'll use for the rest of this article). This means developing the ability to understand, speak, read or write in a language. This is not a conscious activity, but rather training your brain, programming it, more like muscle memory than studying math.
Both are worthy pursuits. Some people are interested in only one, some people are interested in both (I'm interested in both).
However, the great, fundamental misunderstanding, is that most people believe that developing the first (linguistics) will lead to the second (language acquisition). This is completely false.
As Steve Kaufmann likes to quote: