A phrase kept repeating in the 'system's mind as it waited for Jiang Li to be willing to leave the Goddess' world. A wish that could actually escape from that man's mouth.
'I hope I won't be the only one remembering the beautiful memories...'
The 'host' didn't want to be the only one remembering. The system was really like a child when it comes to emotions and feelings so it realized now that all this time, the man was actually hiding remorse and resentment about her lack of memories of him.
All this time, the system thought its host was unfeeling, crazy and, sometimes, heartless and that he didn't care much about her. He was already okay with knowing that in every world, 'she' exists. It forgot that all normal humans could feel emotions.
'Travelling from world to world with only him knowing who the other party is and what they have shared in the past must be quite painful.' The system finally realized.