Open for extension. Closed for modification.
It’s the best design principle out there. Period. I have used it countless times. Every time, it produces a very impressive solution.
But I have to take the effort to implement things the right way.
I love doing things the right way. If only more people did that, things would be much more easier to work with. But on the other hand, it’s easier to come up with elegant solution to bad state of things. But I’d rather have it the other way around.