Sometimes, when there are so many things running in your head, you might begin to lose some sleep. And an hour less becomes two the next day, until all the sleepless hours accumulate.
Even though you feel extra tired today, you continue to work because you can’t afford to take a break. And like a machine, you treat your body to produce the same way you did yesterday, as if you’re still okay.
But like all machines (of course you’re not one), you must schedule breaks just as how they undergo technical maintenence.
Even as simple as a quick nap could make so much of a difference, if you’ll only give it a try.