Procrastination is the act of replacing higher priority tasks with lower priority tasks.
Everyone procrastinates to a varying degree. You have this problem not because you find it difficult to organize and are less intelligent. Procrastination is fuelled by your weakness and failing to think about your future self, evidently your mortal enemy. This is called the present bias. What you want now may be different from what you'd want in the future. Your preferences change over time. This is why you make the same resolution ten times in a row, but this time you mean it!
Our will succumbs to death by a hundred small things you delay, like taking the elevator instead of going up by stairs or delaying the assignment till the last day. Of course, you'll do it eventually, you will get around to it. You will start tomorrow. There’s a growing list of books you will read one day.
Before you do though, maybe you should check your email. You should head over to Facebook too, just to get it out of the way. A cup of coffee would probably get you going, rearranging the icons on your desktop won't hurt either.
When asked to be given instant reward as compared to a bigger reward for which you'll have to wait, most people choose the former. Of course, it is logical to choose the other one and it makes sense with our evolution too, but our ancestors didn't have any homework to submit, nor enough timed rewards so we grew up to choose the shortcut. 'Later' is a bleak place where anything can happen so you choose the present, however inconvenient for our future self. You are not a bad manager of your time, just a bad technician of your thoughts.
“The future is always ideal: The fridge is stocked, the weather clear, the train runs on schedule and meetings end on time. Today, well, stuff happens.” - Hara Estroff Marano in Psychology Today
Thinking about thinking is the key. It's a struggle in your brain with what you want now versus what you'd like tomorrow. It's choosing 'should' over 'want'. There are countless books and more being published every year about procrastination, but it really is just your weak will which can be easily encountered by knowing your flaws and acting upon them(a simple statement, it may seem).
So the next time you have a deadline and you want to watch that show you like, remember that by delaying, you are just defeating yourself in the battle inside your brain.