
“Withdraw into yourself, as far as you can. Associate with those who will make a better man of you. Welcome those whom you yourself can improve. The process is mutual; for men learn while they teach.”
Recede in te ipse quantum potes; cum his versare qui te meliorem facturi sunt, illos admitte quos tu potes facere meliores. Mutuo ista fiunt, et homines dum docent discunt.
Source: Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter VII: On crowds, Line 8.