Friendships are not necessarily built on debts. If the only thing that makes you friends is some outstanding promise or IOU, then that's not really a friendship, that's a business partnership. You have to find likeminded people or at least people that you get along with, and you build friendships by sharing time and resources with each other. This breeds loyalty and makes the friendship stronger.
No one keeps their promises in a friendship anymore. Even when one promises to be there for a friend in time of need, they never come anymore. It's like people are backstabbers these days. Or, when one did someone a favor, they don't even have the decency to try to repay them back. There is no sense of "Thanks, I owe you" anymore.