Not true and that's not what I'm saying. I'm saying that no matter what it is that is being discussed, be it a complex theory of Physics or a simple anecdote on some trivial subject, you should be able to break it down so nearly everyone out there can understand it, barring obvious exceptions of course. And I don't mean to say make them comprehend all of it and to the same extent an expert with a lot of education and experience will - just that they should get the gist of it and maybe a bit more, based on just plain common sense.
And science doesn't always progress in the way you say - there are several ways that's done. You can formulate a theory and test it out practically to see if it holds under the conditions it's supposed to or you could be empirical or you can make chance, accidental discoveries (Serendipity) or you can extrapolate on pre-existing theories and so on. The greater the level you are at, the more specialized and esoteric you will be. But that doesn't mean you should be unable to explain what it is that you are doing to a layman, simply because doing so would mean that you aren't the elite you would otherwise be.
Well it's true that you need to be able to explain concepts that don't involve other concepts to anyone, but some concepts require you to first understand others because they are constructed of and/or involve others. I think we're actually saying the same thing. I'm just saying, for instance, if you're going to explain "hyperplasia" to someone, they'll first need to understand the inside of a "muscle." Again, I think we agree here.
And, by no means was I saying we
always make progress in the way I described. I said "most" because it's true. Science involves a dynamic process of creativity, of tying things together that may not have before been interpreted as interconnected. Many breakthroughs do occur this way, it often requires us to take a few steps back and consider what would be true if what we
think is happening is not, which results in an alternative postulation. Often that alternative postulation, though initially questionable, becomes the accurate theory and hence we make scientific progress. Again, coming up with alternative theories does require creativity on the part of the scientist. But I agree with you, it doesn't always work this way, and of course we make most of our progress in small increments...