I preach SOLID pretty hard, but I think after a certain point it just becomes second nature and a "Yeah, that's just how you do it" kind of mindset. Not all of these principles are applicable to every scenario, but for the most part they're a good guide to writing clean code. Some languages don't even have interfaces to do a lot of SOLID things with (looking at you, python -.-)

But I agree that just because you understand the concepts doesn't mean you know how to affectively apply them. Hell, even for preaching them so much, the architect on my team explained to me a few months ago how I was using LSP completely wrong.

Ultimately to me, it's a great teaching tool; but you definitely need to know when to apply it.