We are like people who are bound with ropes. When we wake up, we feel released. We are again, in control of our movements and we can get out of bed; but until that moment, we're tied.
In a deeper sense, there are people who are tied hand and foot in a variety of ways. For instance, one may find oneself enmeshed in economic difficulty, or bound by financial obligation. One may find oneself a prisoner of circumstances. There are many ways to be bound up in life.