I have a friend who I lent around $20 two years ago. Then again, he took another $30 loan six months ago saying he would pay me $50 all at once in a few days. But then, he stopped picking my phone.
I've had "friends" like that, and I learned my lesson a long time ago: never lend money to friends (or family for that matter). If something goes wrong, you lose a friendship or family gatherings become awkward. But I also believe that, in the large majority of cases, you don't help people by lending them money.