The way you write that is so funny. I'm laughing hard.
Okay, here's one. I was "helping" someone repipe their home. They thought it would save them money. It never does. It's always slower having to teach at the same time. At one point it tells me he has three doctor degrees in various subjects. So therefore, he knows more about plumbing than me. I just laughed.
I came from a family where some of us had doctors degrees, and we knew enough to know when to get help. He did some things his way, against my advice. Later during trim, which he did on his own, he called to tell me he was burning his cabinet. Yep.....that's why I stub out and use compression stops. Maybe a plumber can use a torch in an enclosed area like that and not burn the house down, but not a good start for a homeowner.
Stuff I know...........tons of stuff about how mechanical things work. I have a third sense for it. I'm spatial. I can walk plans in my head.
Things I have a hard time with. Peoples names. Part numbers; no problem, names, not so much. Speaking a second language. That's really hard for me. Ask me how to fix something, or design a home from stratch, easy.
I was doing CAD, self taught in the mid 80's. I can tear an engine down, and rebuild it so it runs perfectly.
But now I drop it off and pay someone to do an oil change. I don't need to do everything.
By the way, that plumbing in the slab is going to be problems. And homeowners don't understand plumbing. It's not something you leave out and GOD takes care of you. You need the dang vent.