Story of time 

Mature people, are have a sense of proportion, many people feel that the relationship is getting better and better, the distance will be closer and closer, in fact, there is a limited value, after this value, the distance is too close, but the relationship will have a sharp decline.The hedgehog effect explains this very well. It is a good thing for two hedgehogs to keep warm with each other in the cold weather, but once they get too close, the thorns will hurt each other.