Yes, I should have blown out the pilot light.
The back burner on one side of my stove would not light. There was no gas to that burner. I banged on it, still no gas, so I started disassembling the stove. When I removed the burner assembly, there was gas aplenty. So, where was the problem? There was no possibility it was in the burner assembly, it was just a large hollow tube to the burner. The valve assembly was obviously working fine. So what could the problem have been?
I was about to re-assemble it, but decided the valve core needed lube so the knob would turn more easily. I got out my silicone grease. Then I removed the valve core, using my finger to plug the hole. I smeared some silicone grease on the valve core. Problem, I had to remove my finger to get the valve core back in. Whoomp! Flames! Yes, I should have blown out the pilot light. I had pliers handy, so I grasped the valve core with them and slid it back in place. No more flames. All was well.
The burner now worked fine. I was not able to figure out what caused it to have no gas. The whole assembly is just too stupidly simple not to work.
Fortunatly, a guest was taking continuous photos of the entire process, so I have really nice photos of the flames. The photo above was taken at the exact moment the core was slid back into place.