I am reminded sometimes when I listen to clients that the things that they often remember after a session are not what I have said, but in fact what they have said themselves. Hearing yourself say something in the presence of another, especially in a non-hurried or unguarded way, without the other person trying to change the conversation, is very powerful.
Too often we can feel penned in by relationships and life circumstances. Patterns of thinking and behaviour can keep us in situations in life that can be unfulfilling, frustrating and painful and may appear as having no alternative options. Once verbalised to a therapist, ideas and thoughts take on a different life. The therapist may just listen or repeat, or comment on the thought pattern, or ask a question about it. The client is then challenged to respond and in the response they might hear themselves saying something different, something new.
Therapy offers a space to access different parts of self, partly by having conversation in which rigid patterns of thought about oneself can get disrupted. It seems strange that this is so much harder to do by oneself. And also that change is promoted by listening to what is already there.