Project management is not as difficult as people make it seem, there are projects that are nightmares and there are projects that flow without a single serious problem.  But you can usually minimize the amount of problems with effective planning.  And planning is more than just sitting down one day after lunch and writing out your elements, it’s a lot more actually. 

But one of the biggest errors I see when people are planning is that they do not assign dates or they assign unrealistic dates, like next Monday or 394,234 days from next Monday.  If there is no date or no realistic date, it is very difficult to reach that date and one of two things happen, it gets dropped because it was missed or it gets ignored.  Either way it is not good.  By assigning a realistic date to a task it makes it easier for the assigned resource to actually reach that goal, which is the point after all.

Regards.