Proof-of-Concept

I designed something last week, and showed it to a manufacturing retailer, an executive. He thought it was "brilliant", and sprung into action (to explore manufacture). It is almost impossible to predict, however, where a design will go. I typically do a proof-of-concept (just enough to show that something will work) or a prototype (a fully functioning model in rough). In this case, I did proof-of-concept, and videoed it. OBSERVATION: Sometimes it's the detail which is the hardest. I had this thing basically working in minutes, yet wife E watched me struggle for hours with some detail. There are three other ideas where I have proof-of-concept at the moment.