I dated a cancer for a bit. He was a fiery cancer with many Leo placements and we had a very strong connection and I love and care for him deeply, but he allowed something from his past to take over the relationship. I couldn't handle the pain his change in behavior caused me and he shut down so allowing us to work through it wasn't going to happen. Sure, being nostalgic on the past can be a cancer thing, but I put it up to human behavior as anyone can let their past run their lives. We would have had something great otherwise.