Procrastination

I wonder how common this behavior pattern is that I observe in myself: I really want/need to be doing "important but not urgent" activity A. I'd like to devote my full attention to A for the whole day, but I can't do that until I finish B, which is less important but comes with a deadline. I don't much feel like working on B, and the deadline is not terribly tight, so I end up doing C, which is some activity like reading list e-mail or blogging that is neither important nor urgent, until B becomes acutely urgent. I do almost always meet the deadline for B, but by the time I finish, another B has come along, the cycle starts anew, and I never do get around to A.