Only those who can control their lower nature, and so are able to forget their own interests, can become good psychologists

From my own personal experience, I would say it is more about having accurately observed within yourself and released/accepted that which is an obstruction within you. People struggle with similar things that come from similar places within and without, although circumstances vary drastically. Once greater balance within yourself through your own healing has occurred, you can see more clearly where/with what someone else is struggling. To avoid ego re-actions on my part, I always ask that my Higher Self runs the show in all thoughts, feelings, reactions and images I receive when I'm assisting someone. As well as with guidance given. This way I feel more comfy that less of my lower mind/ego is involved in someone else's process.