Those friends thou hast, and their adoption tried, Grapple them to thy soul with hoops of steel; But do not dull thy palm with entertainment Of each new-hatch'd, unfledg'd comrade.
If friends disappoint you over and over, that's in large part your own fault. Once someone has shown a tendency to be self-centered, you need to recognize that and take care of yourself; people aren't going to change simply because you want them to.
And though thou notest from thy safe recess old friends burn dim, like lamps in noisome air love them for what they are; nor love them less, because to thee they are not what they were.