Here's the most important thing: never get so close to your old friends that you sink down to their level. If you ignore this rule, you'll destroy yourself. You might think, "But I'll seem unfriendly to them, and they won't like me anymore." Remember that nothing comes without a price. You can't expect to stay the same person if you don't do the same things. So choose: do you want your old friends to love you just as much as before by staying exactly who you used to be? Or do you want to become better, knowing your friends might not treat you the same way?
To this matter before all you must attend, that you be never so closely connected with any of your former intimates or friends as to come down to the same acts as he does. If you do not observe this rule, you will ruin yourself. But if the thought arises in your mind, “I shall seem disobliging to him and he will not have the same feeling towards me,” remember that nothing is done without cost, nor is it possible for a man if he does not do the same things to be the same man that he was. Choose then which of the two you will have, to be equally loved by those by whom you were formerly loved, being the same with your former self; or, being superior, not to obtain from your friends the same that you did before.