Knew it was too good to be true, thought I was getting a general feel for how people thought, but I think I'm now entering a new level of ignorance (a not uncommon state for me, I'm easily confused).
Knowing that you don't know is the first step toward learning something new. Rejoice!
But here is where I think that some historic perspective may be helpful.
After WWII, the American occupiers in Japan were not too pleased with people practicing "martial arts." It seems to me that some cleaver sensei dreamed up the idea of "self-defence" in order to convince the Americans to let them open their dojo and start training again.
As far as I know, no one before WWII practiced anything called "self-defense."
Actually, I don't think either term (martial art or self-defence) really encapsulates what we practice (or the way we really should be practicing.) Thus, its seems, there's a lot of confusion, especially at the kyu-level, about what aikido is and how it should be practiced.