> If something is used once, ignore any abstractions. If it's used twice, just copy it, it's better. If it's used 3 or more times, look at writing an abstraction

I refactor for the second time. I don't like chasing bugs in multiple places.

My rule of thumb is that there are only three quantities in the software development industry: 0, 1 and infinity. If I have more than 1 of something, I support (a reasonable approximation of) infinite quantities of that something.