in reply to How do I know what I 'know' is right?
As you figured out, your correction was entirely proper and helpful. I dwimmed and was lucky that my shiny new perl dwimmed right along. I was only dimly aware of the bug, and didn't think of it in that note.
I'm educated as a scientist, and that helps me know that what I think must be tested. What I know must be questioned. To progress with all that doubt, I need to judge what principles are better than others. And I could be wrong. Anybody can tell me so, and if they respect the same values I have to listen.
Give me that over immutable truth, any day!