The most common thing to say to someone who's hurt by a close aide is "It's the ones most close to us that hurt us the most". It's obvious why. It's as cliched!
In fact it's so cliched that these days it almost doesn't make sense. Hurt doesn't necessarily mean being touched at heart anymore.
All day long we meet people who hurt us - some hurt our pride, some hurt our feelings, some hurt our false confidence, and so on. All day long we let other people's attitudes bother us and we end up being 'hurt'.
Why did our lives get so stressful? How did we learn to be so detached from everyone yet allow one and all to hurt us?