Memoirs of a Camera

Wikipedia says:

• doofus (plural: doofuses) A person with poor judgment and taste
• dolt (noun): a stupid person
• blockhead (noun): a stupid person.
• oaf (noun): Originally, an elf's child; a changeling left by fairies or goblins; hence, a deformed or foolish child; a simpleton; an idiot.
• Idiot (plural: idiots): A common term for a person of low general intelligence.
• Moron (plural: morons): A stupid person.
• Stupid (adjective): Lacking in intelligence.

Yet its amazing that you don't need to use them to make someone feel like one... or at least I have gotten that inbetween lines every now and then...