They enjoy working at the 11th hour. Feeling the pressure that they know they need to get the work done, they are able to get it done quickly and efficiently, much more so then if they weren't working against the ever ticking clock. Also, some people like being busy, and would rather have a million of things to do then to have to sit around and do nothing. Some people find a pile of paper work more refreshing than a break, and would rather have to speedily work around the clock then sit and be idle. They are the "busy bees" of our society, and they keep working even when they don't have to, working all the time quickly is their passion and their love for life is lived through it.
There are also negatives to living such a fast paces live style. If you are constantly in motion, you tend to wear out quickly, as discussed in "Burned Out and Bored" by Ronald Dahl. If you are not moving all the time you can become bored, and you also can miss out on the finer things in life. Ronald Dahl also discuses the problem of sleep depravation becoming a habit for kids who are constantly seeking the next exciting thing to do when they find time, and sometimes compromise sleep for this.