Boogers are a pretty good pick! The reason you have them is because you have mucus, or “snot,” which is the squishy, slimy, slippery stuff made in your nose that you might also feel at the back of your throat sometimes.
The purpose of mucus is to protect your lungs from harmful things like dust and dirt that are naturally in the air when you breathe. The gooey mucus catches these things so they can’t get all the way down to your lungs! Mucus also helps keep your respiratory (breathing) system warm and moist. Most of the mucus your body makes just drains into your throat unnoticed, even though you produce about a quart of it every day!
Eventually, little bits of the mucus inside your nose will get dry and bunch together, leaving you with a booger! See… it’s really SNOT that hard to understand!