A person of any age that epicly fails at navigating in public places, from inside QuickCheck stores to cities like NYC and Paris. In some cases, the "street retard" might head in a way different direction you point them to (as in symptoms of being directionally challenged or walk passed the Walmart they were looking for - while walking.

when you've done something so cringe you can't stop replaying it in your head and it stops you from getting on with your every day life