Very selective memories

I find it funny that I can tell Jacob or Kyle to go into their bedroom and get their pajamas on and three minutes later they come out and say, "what did you ask me to do?" Or I say, "please put your shoes on" and two minutes later when they're playing and goofing around I ask, "why don't you have your shoes on?" Their answer is always, "I forgot." That's a very common phrase in our house. I'm told by my friends that their kids are the same way, especially the boys. With such bad short term memory, it's a wonder these kids can actually function and learn anything! It MUST be selective since the other day Kyle told me that Handy Manny always carries a coffee cup and Jacob even remembered that the coffee cup is red. How is it that they can remember the unimportant details of a cartoon, but they can't remember the basic activities of daily living?