When I'm doing serious thinking about software design / architecture, or debugging/problem-solving, I often find the I have a kernel of an idea which seems full

When I'm doing serious thinking about software design / architecture, or debugging/problem-solving, I often find the I have a kernel of an idea which seems fully-formed but inexpressible. I can "see", in my mind's eye, the different interactions between components (floating around in sort of a three-dimensional space), but it's often hard to put it to paper. For me, the hardest work I often do is to describe my ideas in English text. Source code is somehow easier in some way; possibly because it's more concrete and less "squishy".