wasting time

Why do we waste time? Is it because we're lonely and we'll never get a girlfriend anyways? Is it because we're just waiting around to die? Or is the Facebook page that we're staring at truly more interesting than the real world. For me, it's all about motivation. If a person is assigned 4 reasonable tasks and only has the required motivation to do two; will he do two of the tasks and except little to no gratification? Or will he do none of the tasks because it overwhelms him, is not worth being tolled to keep going or is not worth the bullshit of having to live up to the standard of a "good student." All