If you only had one month to live would you stay awake the whole time to make the most of your days? It makes sense at one level, the problem is your body won't let you. You were created for rest. You'll make the most of your time by using some of that time to sleep. You just can't keep going and going.
A recent Sixty Minutes broadcast (The Science of Sleep) shared some interesting research on sleep. They said that if you only get 4-5 hours of sleep for one night, it will impact your mental functioning the next day. The more nights you deprive yourself of sleep the greater the mental impact. On the other hand if you get a good night of sleep your memory is actually better than if you stayed up studying all night. So it pays to sleep. It pays to rest.
As you look at your habits do you factor in down time to recharge your batteries? Do make a day your sabbath? Do you get eight hours of sleep? Do you take time to visit with friends, talk to God, read, take vacations? These are the "useless" things that actually make you more productive in the long run.
To get the most out of your last 30 days be sure and rest!