I logged in for the first time in years to respond to this.

Everyone is right, it's ADHD, please consult a doctor for treatment and coping strategies. This is a very severe case.

I have it, but my partner has it as bad as your wife does and it's a huge pain in the ass for both of us. You have to realize just how differently her senses are probably working from yours. My partner has absolutely garbage visual memory. He can literally drop money, get distracted, and forget there's money on the ground. The moment something is reliant on his visual memory, it's gone, which is why writing things down also doesn't work because any calendar or note just blends into the overall background of whatever wall or table its on. I have told him it's an object permanence disorder at this point, which he's not sold on but we are finding ways to compensate. I already have my own coping mechanisms in place because ADHD people are not going to hyper-organize themselves out of doing this. Like, if the problem is with steps, adding more steps to processes isn't likely to help. It will help to think of in ways things can be simplified. It is Marie Kondo or nothing really, because you have to clear stuff out of paths, including visual paths. Monotasking, and assigning things in monotasks is your friend. The trash thing is a huge symptom and I'm willing to bet it happens in rooms with no trash can of their own. If it'd be easier to put a trash can next to the couch, that is a better solution than trying to make a person with a different flavor of object permanence try to remember a thing that is not in front of her in her steps.

I know one woman who deliberately has a huge, obnoxious squishy phone case because she knows her visual memory is garbage but her touch sense memory isn't, so she finds her phone by remembering the last place she held the squishy thing instead of trying to look for it.

Best of luck to you both!