First things first, procrastinating is the most obvious show of lack of responsibility and with it arises the forgetfulness because its amazing how with such ease a person can convince themselves that they just forgot to full fill their responsibilities. Apart from the artificial factor of forgetfulness, if your just generally not sharp and cant seem to keep a track of things, then that counts as irresponsibility as well because phrases like, "It completely slipped my mind" and "I got caught up in other things" are not valid excuses. They only show how unorganized you are and depreciate your mind.
Similarly getting caught up between two tasks shows disorganization but for instance you were in situation where these tasks were to be completed in separate destinations over a 1000 miles apart overnight, it would be quiet a challenge and even more of an achievement if met.
Last but not least, the mood factor, the equivalent to the apple in eves garden when it comes to responsibility. But of course it tastes good, but only for a while. You can try to ignore and avoid your obligations but not forever, they'll always be waiting for you. Theres no escaping it so whats the problem with facing it. The most common excuse in this case is "I'm afraid", and it sounds like a valid reason because the effect implies that the person is not ready to face this responsibility, but the truth is, they cant know that unless they face it and fail.
The principle behind all of this is simple, do or die.
