Welcome to "Conquering Your Fears: 101." Judging by your dream report, you graduated from this class with flying colors! Your dream is an excellent illustration of how people can learn to conquer their nightmares -- by facing up to the fears they always represent.
In younger people's dreams, monsters tend to be symbols for a wide variety of fears. As kids in a "big person's" world, monsters often represent adults we know (or have seen) who frighten us. Adults, like monsters, are bigger and stronger than we are; and sometimes they can act mean, get angry, or yell at us -- for no apparent reason.
Based on your dream, we don't know what in particular you used to be afraid of. It may have been fears we all face growing up: doubts about our abilities, being nervous in social situations (like at school or with friends), or problems with your parents or family.
Once you decided to face your fears (you got tired of jumping down the stairs) the monster never came back. What's the message of this dream? Monsters, like our fears, grow bigger when we "put them in a closet." This is why it's important, when you have a scary dream, to figure out what's making you nervous. When you look at a monster straight in the eyes, he immediately starts to shrink -- and usually leaves for good.
Congratulations on having the courage to face your fears!