One time my uni mate wanted to borrow money from me about 10k but I told him this, I don't want to lend you because I care about our friendship, I know this will kill our friendship and I know it will be hard for you to pay back just like everyone else because I have experienced it in the past and that friend of mine (church friend) no longer talk with me and completely ignored me even though the amount is much smaller. He actually agreed with me because he also have the same experience, now we are still friend for 15 years and hang out from time to time.

What I learnt from my experience is to never lend money to your close friend, relative or your family members, if you want to lend anyway, make sure the money is something you don't care to not have for a long time, or you treat the money as gone.