When you get home from school, your mama says to hang your spoons and arrows on the coat rack. That doesn't sound like something your mama would say, and you begin to doubt that she's your mama at all! She usually takes them and washes them in the sink. You doubt you could hang them on the coat rack even if you tried.
Your doubt is growing really strong, so you decide to test your mama by putting her head in a guillotine (ぎ)! Oh come on, don't feel bad, you're preeettty sure this isn't your real mama.