"Posing the question is a large part of the work. If you have never seen rope, it actually doesn’t occur to you that rope would come in handy, or to ask yourself how to make some."
Sorry @quadrangle, I would go towards an opposite opinion than yours :) I have never in my life been in such a time when inventing would be as easy as now: It's so easy to communicate through internet to find people and skills to fill the ones I'm missing. From crazy idea to proof of concept is pretty straight forward.
For example if you have invented something including electronics:
You have no knowledge of it? PCB (https://en.wikipedia.org/wiki/Printed_circuit_board) knowledge -> buy some from freelance.net. Basic component drawing with pen and paper is OK to ask a quota for. And when you want to build the PCBs -> alibaba.
And proof of concepts can be built even with more simple parts, such as Arduino, piece of metal can, etc.
(Edited some typos and bad English.)