Every parent must assume a life-long bond with their child, one that grows increasingly close and rewarding, and when instead that bond disintegrates, it must be immensely painful. Even more so if the child dies.
I thought of that when I was reading about Christianne Boudreau, the Canadian woman whose son Damian became a Muslim, joined Islamic State and died in Syria at the age of 22.
How does she come to terms with what became of him? How does she cope with such a profound loss?
One thing she does is to remember him as he used to be, before his conversion, before the estrangement. "To me he was a young man who was compassionate, caring, loving and protective. That was the boy I knew. I'll always remember him as that. Not for what everyone makes him out to be."
She also supports organisations that are working with families to stop a loved one embracing fundamentalism.
But it's a common dilemma for parents. I've read of wealthy couples whose child disowns them, scornful of their affluent lifestyles and shallow values. Or stiff and starchy, penny-pinching couples shunned by a child who prefers a more spontaneous, freewheeling way of life. Or a new step-parent rejected by a child who's loyal to their original parent and sees the newcomer as an unworthy chancer.
Once a gulf like that develops, it's very hard to bridge it again. Too often, both sides become set in their ways and the stand-off continues indefinitely. They say blood is thicker than water, but that's nonsense. Families can break as easily as friendships. And the fracture can cause unbelievable pain.
Pic: Christianne Boudreau