Shared parenting works better when both adults know the ordinary details, not only the emergencies.

One adult usually ends up carrying the list: the shoe size, the friend who has turned difficult, which form is due Thursday. Involvement gets counted in the big moments while that running knowledge sits with a single person, invisible because it never looks like an event and never finishes.

Take one ordinary domain outright rather than offering to help with it. Own the remembering as well as the doing, and resist asking where things are kept until you have looked twice.