Try to think of stupid things you've done in your life - similar to the laundry example.
Think of your ADLs, your hobbies, cooking or following a recipe, even school related. Surely there are things you've done where you've said "Duh!" when you realized you made a mistake.
It sounds to me like this is an exercise in realizing that even simple things that are familiar, like laundry, are processes that can have inherent errors. In nursing, most of our tasks become second nature which can lead to process errors. So to me it sounds like it may be best for you to sit down and really examine your life and tasks to determine where errors have occured. It makes a good exercise for when you're a practicing nurse.
If you want to bounce off your ideas, go ahead. We're here to help.