So we got home and re-lit the pilot but it kept going out. A friend told us to replace the thermostat before taking anything apart in the floor. If the thermostat (which was 40 years old) was bad then there would be no spark to run the heater which somehow caused the pilot to go out. The thermostat unscrewed from the wall and had only two wires, red and white. A new thermostat cost $17 at Home Depot (we went
Seeking out a solution in the actual unit would have required taking things (what's a thermocouple?) apart in a tiny crawl space in the dirt which would have taken more than six minutes and in this case not fixed the problem.
I think there are several ways to apply this (this being simple and cheap) to investing in terms of strategy, products chosen, method of analysis and anything else you can come up with. Just keep it simple relative to the time you want to put in and stick to cheap, easy to understand products. Like many things, investing doesn't have to be that difficult.
I found this image on a post from Prieur du Plessis. Hopefully we won't end up needing two or three of these to go to the grocery store.