Long Lost Family. I can only watch it with the SO isn't around. He's adopted and I know he has zero interest in finding his birth family.
This stuck a chord with me, cos my Dad was the same. Couldn't blame him. He had scars all over his body when he came to Nan, as a toddler, on account of physical abuse (by stepmother, as it transpired) , He knew he's had an older brother and older sister, but felt bitter towards them because they hadn't bothered to trace him, as he supposed.
His siblings actually had tried and tried, but it wasn't so easy back in those days, especially not in the event that his new parents had changed his forename as well as his surname. My sister took it on herself to track them down, just a few years before Dad died. And he died a happier and much less bitter man after hearing his older sister's story (the brother was dead by then, sadly)
You just never know.