Strange experience with cast iron

I've had a griddle for a few months now, and I have started using it more lately. I've cooked maybe a dozen or so times in it. It was properly seasoned when I got it, and I mostly use it for bacon, often followed by things like eggs, mushrooms, toast, etc (why bother with the toaster when putting bread on the griddle for a few seconds seems to work fine?)

I have not been using soap, just hot water and a gentle plastic brush, and washing-drying-applying olive oil on it right after use. My roommates have not been allowed to (ab)use it :)

It has now gotten to the point where, after cooking on it today, and using a flipper to get the food off, there was nothing left on it to wash. I mean the coating is there of course, but there was nothing extra. Since you're supposed to leave the coating, letting it build up, and there was no extra food, I just left it on the burner for a couple of minutes while I was eating, and put it away. Bacteria is supposed to be end when you preheat (hence why not using soap is ok) so I couldn't think of a reason to wash 'nothing' off

Comments?