My ex-husband was a counselor and he did not like the phrase “I know.” He said we do NOT know what other people are going through and we can never know. Saying “I know” makes it seem like their stories, complaints, troubles, and highlights are common and not individual.

Here said if you need to say anything, say "I hear what you are saying. Please go on."

I have tried not to say “I know” when people tell me anything. It is better to hear what they know and learn something new.