Umar b. Khattab رضي الله عنه reported:
I donated a pedigree horse in the path of Allah. Its possesser made it languish. I thought that he would sell it at a cheap price. I asked Allah’s Messenger صل الله عليه و سلم about it, whereupon he said: “Don’t buy it and do not get back your charity, for one who gets back the charity is like a dog who swallows its vomit.” This hadith has been narrated on the authority of Malik b. Anas رضي الله عنه with the same chain of transmitters but with this addition: “Don’t buy that even if he gives you for one dirham.”
[Sahih Muslim Book 012, Number 3949]
Someone I know is having a tough time letting go, due to the amount of time, energy, and money they have invested in the relationship. Perhaps remembering this famous hadith might help in letting go of both the things and the person associated with those things. Worldly goods can sometimes prove such a hazard to peace of mind.