If i realizei hit myself, no bruise. if i don't realize, why does it bruise?

i get bruises adjectives the time, especially if i don't know i've hit myself with something. but i know i've run into something and it hurts, why doesn't it bruise as glibly?If i realizei hit myself, no bruise. if i don't realize, why does it bruise?
A contusion (bruise) is the result from a blunt force trauma,like a fist or other not easy surfaces coming in contact next to the body.It turns black & blue because of the tiny blood cappilaries are fragile,and lie vastly close to the surface of the skin,and they rupture,causing the discoloration.Some areas of the body the skin is thinner,and more straitlaced,like the facade etc.Some people lately bruise easy,some hold a certain,vitamin deficiency. Some times its a sign of blood condition or disease. Take care. SW RNP
basically put some ice on it and the sweeling will travel down the bruses will go away after a while it jujst busted amenable capilarys you will be fine