OFF TOPIC re: doofus
I grew up in the Ozarks of the US. [Hillbilly country for y'all highfalutin folks from across the pond.]
Doofus can refer to a likeable guy who is just not very sharp at times.
A doofus probably grew up around people that Jeff Foxworthy spoke about in "you might be a redneck if..."
Sometimes a doofus is pretty limited financially. For example, when i was growing up, i used to dream about having enough money to afford to have a washing machine on our front porch, like the rich folk.
Next is the absolute truth. When i went to college, i knew it was not correct English, but i was in the habit of saying y'all to refer to 1 or more people. There i met people who instead said you'uns.