It depends how you define "useful" and "helpful". The only time I ever here someone use that phrase is when their authority is being questioned. So you have a problem now: I am having my authority undermined; how do I get it back? Boom* "Because I said so." When you say this, you take the wind out of the sails of the person questioning your authority because there is nothing you can say to retort "Because I say so." However if the person chooses to ignore your authority either way, it is time to show them why you saying so is reason enough for them to do it. Otherwise you're just blowing steam and have absolutely no business using the empowering phrase, "Because I say so."

by Anonymous 10 years ago