That sound you're hearing is my head, ringing like a bell that's been given a bloody great whack with a fifteen pound sledge. We just covered "design by interface," which, from the comments, is quite familiar to at least some of you but was a concept I literally could not get my head around reading about it in books. I think I tried to teach myself Java and C# at least five times in ten years, and foundered every time on this concept. It would finally seem that, with the help of a harbor master, I have managed to steer clear of those rocks.

I now know what a nineteenth century shipwright must've felt the first time he ever saw a steamship under way.