When have you been told “Never tell a Mother / Father how to parent their kids”?

I was once told never to tell a mother or father how to parent their kids when I was trying to give advice on how to handle a particularly difficult situation with their child. It was like trying to teach an old dog new tricks – they had been parenting for so long that it was hard for them to accept any outside advice, even if it could help. In the end, I had to accept that parents know best and just trust that they would figure out the best way forward for their family.