The perceived need for people to “find yourself” is more typical (I think) of the loser mentalities which accompanied the arrival of Nietche, Sarte and their kin in the first wave, and even sadder would be social theorists such as Benjamin Spock and the Beatles in the next.
But if there is a citation to an original source from which this Jeffersonian alleged quote may be found...
Arrg...should be “not prone to pop psychology”.