The ארחות צדיקים devotes an entire chapter to the subject of laziness. Often laziness can become a serious obstacle towards achieving one's goals. The lazy person is expert at finding excuses to avoid doing what he needs to do. It is most interesting that the ארחות צדיקים says that there is a connection between laziness and sleep. The best way to hide from responsibilities is to convince oneself how tired he is and how badly he needs rest. Sleep begins to be an obsession. On the other side of the coin, you have a person who is filled with energy and motivation. He often pushes himself further than his own limitations. He tends not to look after himself as he should. For him, sleep is a necessity because he probably doesn't get enough. But for the lazy person, sleep is a huge hindrance. This is another example of the wisdom of the rabbis and their keen insights to human nature.