I was 18, she was ageless. I was young and searching, she was wise and knowing. She was my teacher in my seminary in Israel, and I was open for mentorship. I think I even made up a few questions for the sole purpose of connecting with her.

And connect I did. She became my person. I bounced things off her; I visited her Friday night after candle-lighting. She was generous with her time and wisdom. I felt understood and appreciated. I asked for advice, knowing that I might not always like the answers, and that that was OK. I welcomed the self-awareness that comes from honest and loving critique.

Our relationship continued when I moved back to Israel as a young married woman. I continued to visit and bring my babies. I moved back to the States and called her when I needed advice. She helped us decide which school to send our kids to. It felt good to know that I could continue to turn to her; that she understood me and cared about me.

As I visited Israel through the years, I tried to see her whenever possible, but the visits thinned and became less frequent. I was changing in different ways as I came into my own. And then one visit was different from all the other visits.

My mentor mentioned a project that I had been involved in. And in a very very subtle and not unkind way, she suggested that she was surprised I was involved with it – that it was beneath me. As my stomach dropped, I maintained a respectful and conversational facade, but something in me shifted forever.

I never visited or called again.

Times change and people change. The mentor I develop for the 18-year-old me is not necessarily the mentor I will need two or three decades later. So much happens to alter our realities and our mentors don’t always keep apace with those changes. A mentor is not necessarily a mentor-for-life. Mentorship is a very private, personal matter. It cuts to the very fragile and vulnerable core of who you are as a human being in all your strengths and weaknesses. Sometimes mentors need to be updated.

But more globally, let’s talk about criticism. The power of criticism, I’ve learned, cannot be overstated. For years I felt guilty about “dropping” my mentor – but with time came awareness. When I had asked advice, even with trepidation, I was a vessel open for receiving guidance. But when it was offered with no context, I was shattered. Instead of feeling grateful and appropriately guided, I felt misunderstood and underestimated. No matter how old you are, you want your mentors to think well of you and assume the best about you.

Criticism is perhaps the most powerful tool in the box. It can build and it can kill. Unsolicited criticism can ruin a relationship. Usually it will not empower the person to change – but it may well empower him to end the relationship, whether literally or internally. Criticism kills honesty in a relationship and is a signal that you can’t actually be who you are. You’re not good enough and you are not approved of. If the goal of criticism is to foster growth, we should be terrified to offer it because it usually achieves the opposite.

I’m also at fault here. I’m extremely sensitive to criticism. Maybe more than most, maybe not. Maybe we should all grow a thicker skin. But if people are that sensitive to criticism then whether they’re justified or not is irrelevant.

I’m not proud of this story. But I put it out there to see what can be gleaned. What do you think?