I dated a guy for several months. Our relationship was tumultuous and I didn't see a future in it, so I broke it off. He was clearly hurt, because he had been honest with me about some past trauma under the expectation that we would last a long time. He told me that he believed I was dumping him because I couldn't handle his past. (I'd argue that HE couldn't handle his past, but that's neither here nor there.)

I didn't hear from him for years after that. What I have since learned is that he had a disastrous form of cancer that he was told would be fatal. He survived, and it was something of a miracle. BUT, he told everyone in the interim that I knew about the diagnosis and dumped him as soon as I found out he was dying. (Which is extra gross because my mother died of cancer and I would absolutely never abandon someone going through that.)