Plus-plus as a model of the creative process

My 4 year old son is currently playing around with Plus-plus, which is a construction toy not unlike Lego. The main difference is however that Plus-plus only has one type of brick (in many different colours), shaped as two joined plus signs (see figure below). The shape of the bricks has implications for how they can be joined up and consequently what type of patterns one can construct. For example it is impossible to construct a square since it will be jagged along the edges. Any shape you can imagine can thus only be approximately constructed with Plus-plus, and this is where my frustration sets in. I have clear idea of what I want to build, say a dog, but the substrate won't let me. I'm trying to be creative, but Plus-plus is putting constraints on what I can express. Of course the same happens when I build with Lego, but in that case I have already internalised the constraints and they therefore don't bother me to the same extent. I think the same holds true for any other creative process, such as doing research. The methods that we use for joining together known facts into as of yet unknown facts constrain our creative process. But most of the time we are not aware of our own limitations and happily build our jagged truths that only make up a tiny fraction of what could possibly be expressed.