You've told your kids to put away their toys, put on their pajamas, and brush their teeth. But when you check on them later, they still haven't done the things you've asked. When you ask them why, they tell you they forgot. In fact, they use this excuse so often that you begin to wonder: Are they really so forgetful? And if so, why?

Whenever you're given a list of things, that list is stored in what scientists call working memory. This is a temporary storage bin in your brain that records the stuff you need to get something done. For example, your working memory remembers unfamiliar phone numbers for as long as it takes you to dial the phone.

Like the contents of a computer cache, the contents of your working memory are eventually flushed out, freeing your working memory for more pressing needs, or else they're stored in your long-term memory so you can use them again later.

While scientists have discovered that a kid's working memory holds, on average, one less item than an adult's, the jury is still out on why this is the case. Is there a difference between the capacity of the adult brain and the child's brain? Or do adults have better-developed strategies for remembering?

Regardless of the correct answer, this suggests that your kids probably aren't making excuses when they tell you they forgot. To make things easier on them, try breaking lists down into small chunks. But if that doesn't help, don't worry. They'll grow up eventually. Although they still won't do what they're told, it won't be because they don't remember.