My great-great grandfather, William Sim, came from Aberdeen (am guessing the city specifically) and. was described on his wedding notice in Long Island, New York in 1837 as William Sim, Esq. As far as I can tell, he never returned to Scotland.
His father's name was not mentioned in either of his two wedding records and I have not been able to find a birth record on Scotlands People.
With the surname, Sim, is it more likely he added the Esq out of self-importance, rather than because he was the son of someone important who may not have registered his birth in 1816?