I think I've gotten the hang of home electrical wiring.

I've done a number of things, from installing new outlets and lighting, to troubleshooting minor homeowner-fixable problems. Each of these projects were just carefully following a map of black wire here, white wire here, green wire here, but no real understanding of WHY each of those needed to go where they went.

But yesterday, it kinda "clicked" as I was rewiring the ceiling lights and outlets in my ever-incomplete bedroom ceiling remodel.

There was this tangle of wires inside a vintage junction box.

I was trying to carefully remove each of them, and map it all out... when I realized what was going on.

I pulled out a piece of paper, drew out the wiring the way I thought it should be, then confirmed that it was actually wired that way inside this Junction Box of Doom!

So I cut all the old wires, ran new wires and a new outlet, put it all back together...

... and it didn't work.

But I now know why. Just a loose connection, really. (Turns out that getting four heavy gage wires to make a reliable connection to each other is a pain in the butt. I'll fix it tonight.)