I think you might be misreading what I wrote. While your points are correct, I was specifically referring to "off-by-one mistake", which is a common "silly" err

I think you might be misreading what I wrote. While your points are correct, I was specifically referring to "off-by-one mistake", which is a common "silly" error (since many indices are zero-based, it's often easy to request one too many elements, or chop off the first item). Also the way you quoted me above, "make sure you didn't make a stupid off-by-one mistake" looks like it's talking about writing just enough tests. However, in context, I'm actually referring to writing unit tests for small items where you might make a stupid off-by-one mistake. So I was never referring to "one-off mistakes", as in mistakes that are flukes. Your points are all good otherwise! Never rest on your laurels and always think about what you can do to catch your mistakes.