[mikewarot]

I'll never forget the time a fellow member of PS1 in Chicago, a programmer, had his intuition broken by an Arduino and a set of LEDs. He built a project pretty much as described but as the Arduino turned on multiple outputs, each LED got dimmer.

It turned out that he knew that it didn't matter which side of an LED a current limiting resistor was on, the circuit worked identically. It thus seemed reasonable to refactor several separate resistors into one, to save parts.

A perfectly reasonable conclusion from a programmer perspective, turned out wrong in terms of circuits. Practical lessons were learned.

Getting a 3d printer and learning CAD offers similar challenges, and expansion of your world view. Some intuitions will turn out to work just fine, the exceptions are where you learn new things.