Do you remember the felling when you bought your brand new laptop and you promised yourself that you are going to keep it knew? What happened?
I'll tell you what happened 'you got used to it'. So used to it that it didn't feel new anymore. You or anybody in today's world would probably use it so frequently on any place, couch, seat, chair, pillow, table, car seat, school book bag, office bag, work place & etc.............I mean the list of areas for the computer to collect unlimited dust is limitless!
Oh and here is the BEST PART! How about when the computer is used even when its not used such as Standby or Hibernation mode. I cant imagine how much dust it will collect from there alone and most importantly where is the laptop physically standing while its in that mode!
Last but certainly Not Least, when it's the day of the week to clean up your room is the laptop included, or is it already in the backpack so the room is already halfway clean!
All I am saying is pay close attention to how the computer is managed, used where, when and clean it when you have the chance before it collects too much dust, lint and becomes stuck to the cooling fan where you would have to take it to a professional to clean it up on the inside unless you are willing to risk it opening the laptop by yourself!
I have to warn you laptops have very small,expensive, sensitive parts!