Forgetfulness is the name for the habit or the moment of often forgetting. It can be light: a moment of forgetfulness, like leaving your phone on the table. It can also sound a little heavier when people talk about getting older. In careful talk it is still not the name of a disease, though everyday speech sometimes stretches it that way. The word lets you talk about the thing itself (“forgive my forgetfulness”) without pointing a finger at a person quite as hard as calling them forgetful.