A dumbass is a person who "doesn't know" how to do or what to do and tries to either inject their opinion or effort not knowing what they are doing.
Don't believe me as someone who has true intellect that is older then 80yrs and they can tell you I am speaking what they learned. I was young and asked many people who all were my grandparents age, I am 39 currently and I am said to have an old soul however that is a phrase for wisdom beyond my years. Meaning I collected knowledge form people quite q bit older to have an understanding of the true definition of words we have since lost our foundation and it would be nice to get it back or retain what little we still have here in the USA
(when all else fails read the instructions Smartass)
Phil gets the same prefab item and instuctions, he reads the instructions and doesn't understand what the instrucions are saying and still tries to put it together and has the same left over pieces.
(when all else fails and the instructions are beyond your grasp ask for help Dumbass)
Jerry gets the same prefab item and instructions and follows the directions, he has no left over pieces when it is completed. He comments on Phil as a Smartass and Jeff as a Dumbass and says your both stupid. Therefore he is a Wiseass and a Jackass for the uncalled for commentary, with the smartaleck remarks.
CrazyChick: Hello room.
You: Why the fuck are you talking to a room.. There are perfectly good people here.
CrazayChick: Fuck you man Damn smartass.
Smartass: Cause you came in... we made it that way to annoy you. (hyuk, hyuk)
(not exactly the opposite of dumbass because a dumbass really is an idiot but a smartass isnt neccessarily a genius)