Some people don't need a top level goal because they have their priorities in order. I think maybe the reason why it helped me is you know everyone's got an inbox and probably everyone feels like their inbox is a little more full than they would like. If I don't have some way of making those choices that is the ultimate why from it's like well what am I doing otherwise I just end up becoming a people pleasing machine.
Also: should we all have personal mission statements?