Retire into yourself as much as possible. Associate with people who are likely to improve you. Welcome those whom you are capable of improving. The process is a mutual one. People learn as they teach.
Seneca the YoungerThe place one's in, though, doesn't make any contribution to peace of mind: it's the spirit that makes everything agreeable to oneself.
Seneca the YoungerThe things which we hold in our hands, which we see with our eyes, and which our avarice hugs, are transitory, they may be taken from us by ill luck or by violence; but a kindness lasts even after the loss of that by means of which it was bestowed; for it is a good deed, which no violence can undo.
Seneca the YoungerWe are so vain as to set the highest value upon those things to which nature has assigned the lowest place. What can be more coarse and rude in the mind than the precious metals, or more slavish and dirty than the people that dig and work them? And yet they defile our minds more than our bodies, and make the possessor fouler than the artificer of them. Rich men, in fine, are only the greater slaves.
Seneca the Younger