I recall hearing that if you always do that, eventually you reach the point in which you CAN'T do something unless there is inordinate amounts of pressure on you, which can contribute to heart failure later down the road. Generally not the best of paths to take.

That being said I tend to procrastinate quite a bit, but I don't really stress about anything so it doesn't bother me when I'm fighting a deadline since my attitude is generally "two hours? Plenty of time!" and not "OH MY GOD ONLY TWO HOURS I'M GOING TO FAIL OH MY GOD WHAT DO I DO WHAT DO I DO!?"