Paying the bills. When we got married, my wife had never written a check in her life, much less balanced a check book. I handled all the bill paying, of course. Fast forward 7 or 8 years. My appendix busts on Labor Day. I am in the hospital until Thanksgiving. She obviously had to take over paying the bills. Taught herself what she needed to do, asked my mom for help on things she couldn't figure out. That was around 72 or 73. I may have seen the family checkbook a dozen times since then. She keeps this huge hand written chart of the bills and has her own filing system. I tell her to put it in a spreadsheet or something, but no. She trusts hand written.
Things we are not capable of. I'm not great at dish washing, but I manage when I have to. She doesn't like the way I do it, so it's not too often. But I am incapable of making a bed or ironing a shirt. At least to her satisfaction. If I make the bed, she will remake it immediately. Ironing, she just won't let me do, because then she has to get all the creases out of where they don't belong.
On the other hand, she is not allowed to touch an extension cord. She can pick up a neatly coiled extension cord, move it three feet, and when she puts it down, it's a very large Gordian knot. When we were remodeling the house 30 years ago, she would tidy up every night when the contractors left. It didn't take them long to start taking their extension cords with them, because she would make on impossible tangle out of 3 or 4 hundred foot cords.
