It just means that it stays in your system a lot longer than a med with a shorter 1/2 life. I had similar experiences with Valium and stopped taking it. I was on it about 6 months before I quit. I was tired of feeling tired and cranky all day. I have switched over to Xanax which does not leave me tired but it has a short 1/2 life meaning it is eliminated out of your body pretty quick, so rebound anxiety is sometimes a problem especially if I am stressed.