Un Anillo para gobernarlos a todos
I have concluded that learning a foreign language is actually impossible. I base this theory on the fact that I have repeatedly failed, and I used to consider myself smart.
This hypothesis has a number of easily testable conclusions, so it has the key attribute of a proper Kuhnian theory, unlike some others I could mention. One clear implication should be there aren't actually any people who speak multiple languages. Of course there do appear to be such people, and I even know a few, some of whom appear to read this blog.
At this point I need to become a Diracian, and not let a beautiful theory be slain by a few inconvenient facts. One possible explanation is that those who actually appear to speak two languages, or more, are actually multiple people, perhaps identical siblings separated at birth. Or perhaps they hold a ring of power, and hence have the power to understand the thoughts of others.
Just in case, while my theory awaits scientific confirmation, I'm going to continue to flail away at Spanish.