My wife and I are both terrible at tracking our spending because we use different credit cards and apps, and we keep thinking we're doing better than we actually are because we each only see part of the picture, but neither of us wants to be the one to aggregate everything and face the real numbers.
More people experience this than they realize.
Mental accounting and avoidance bias are allowing you both to maintain comfortable illusions about your financial reality.
“Where Are You with Behavioral economics — biases in financial decisions?”
If this sounds familiar, the Library can help you find the bigger picture.