I asked this question to my Rabbi last week and my Rabbi quoted for me an interesting story about the Rebbe Maharash. The story goes as follow (paraphrased):
The Rebbe Maharash would have personal meetings with Chassidim at night. There would be a line of people waiting to get in. One night, the secretary of the Rebbe Maharash came out and said that yechidus was paused. The Rebbe would take no more visitors for the next few hours. The people waiting were confused and upset. Many had waited a long time to get in and had traveled from far away. But that was the decision. So they waited. A few hours later, the secretary came out and announced that yechidus had resumed. One of the Chassidim later asked the Rebbe Maharash why yechidus had to be paused. The Rebbe related that in order for him to help another person, he needs to find that issue reflected in himself in some way. This time, a young man had come in with a story about a sin that he was doing. The sin was so unusual and extreme that the Rebbe Maharash could not find any part of himself that related to the sin. He spent many hours meditating, trying to find the internal aspect that could allow him to connect to this young man. After a few hours, he found it and was able to help him.
Does anyone know where this story has been originally told or where this story can be found online?