I recently realized that I had lingering old pains and those were triggered by someone going through a similar experience and I literally felt their pain. It took me a lot of digging in my mind, peeling off layers, to understand even what the root pains are.
Sending a message to someone and potentially not getting any (meaningful) back is something I find very hard to accept, though I know not responding is often not on purpose.
For me, it is not so much about an electric fence, more about a feeling of rejection or abandonment that seems really hard to eradicate.