Imagine having to wind a mechanism to start your brain. Sometimes winding it all the way will last you all day, but the mechanism gradually winds down, sometimes so slowly that you don't even notice it. You've got so many other things to worry about. So you develop a habit of winding it a little every couple hours. But sometimes you forget, you're thinking about your schedule, or trying to remember dates on a quiz. And when you don't wind, even more slips away. You forget to call someone, even with reminders; you wind.
This is having ADHD for me