Messages prefaced with the words "nothing to worry about" are almost always guaranteed to have the opposite effect.
And so it was the other day, when a text from my eldest son, Sam, began with this classic prologue.
In this case, it read "nothing to worry about, but.... just been verbally abused by a stranger calling me a 'f***ing Jew' on the Tube."
I didn't even have time to appreciate his deferential asterisks before dialling his number in frantic panic.
It turns out that as Sam and his girlfriend travelled the Northern Line on a lunchtime train, a complete stranger who appeared to be Muslim, began screaming at him for being Jewish. He also called Sam and his "people" murderers for killing "my people".