Rachel, who I shall call Nigella

, you have touched on a description, which I can bring up to date.
"Been there, done that, got the T-shirt"
We all know the shared experiences we are talking about when those words are spoken between friends, family and colleagues.
My point is that by using your contribution, which alludes to this is to say,
"Had the disease, had the operation, got the scars."
I belong to a group of people who have to undergo regular sessions in a particular field of medicine. The members of the group are far and away better informed and cognizant of each others' struggles than all of the medical staff with their expertise and text book learning.
You rightly used the word 'empathise.' It is a word I have used with special care in some of my postings.
Imagine you are at the bottom of a deep well. A face appears over the lip of the well and a voice shouts down to you saying, "I know how you must be feeling and I do sympathise with you."
You and I know that it is just words.
However, while you sit at the bottom of the deep well, a voice beside you says,
"I know exactly how you are feeling. I'm stuck down here as well, .......in this well."
That is the voice of empathy and I will listen to it.
There is no desire to inflict a similar condition on another, in order for that person to at last, understand exactly what you are saying.
It is simply that they have no idea and will never know.
I posted a poem on the board ages ago. I think it is called "To my prison psychiatrists." I wanted to expose the yawning gap between those who are trained and paid to be experts, and those who are experts through a real world experience. I haven't looked at the 'poem' to support this particular thread and I won't look at it now. It is one of my written 'children' and it has been sent out into the world to make its own way through the ether.
Byron 'sends Nigella his regards.'