"Out of the frying pan into the fire" was there, and "The grass is always greener on the other side of the fence" - but not the priceless primary school howler recently published in the TES's Friday magazine: "Look after the penis, and the pounds will look after themselves."
This week's list of 67 violent, unteachable pupils, identified by the National Association of Schoolmasters Union of Women Teachers, reminded me that "the child is father to the man". Unless we do something about these disruptive, disturbed children - and others like them - they will become the suicides, drug abusers and inadequate parents of the future. Above all, they will fill the jails.
We know, of course, that a certain amount of difficult, even criminal, behaviour around the age of 15 is common, and most young people grow out of it. But children who attack adults and seriously injure other children, especially in primary school, are not going through the normal difficulties of adolescence. And teachers - whose job is to teach, not to act as psychiatrists or prison warders - should not be expected to manage them.
I was somewhat mystified by the news that one in three expelled pupils is then reinstated by school governors on appeal, sometimes in the teeth of opposition from the teachers. This suggests a breakdown of trust between the school and the governing body.
Schools do sometimes treat children unfairly and may not take enough account of the difficulties of their lives outside school. On the other hand, all the special pleading: "It wasn't me, miss, honest," and the tedious excuses, fabrications and blaming others (by parents as well and pupils) are heard day in, day out by many teachers. Governors can be a softer touch.
Of course violent children need an education, but not in the mainstream until their difficulties have been resolved. We need a proper network of referral units for children with serious behaviour problems. There used to be some anxiety about "labelling" such young people. This anxiety is misplaced. The enormous range of problems that most of these children have cannot be addressed if the authorities are too squeamish to identify them.
The Government should not palm this national crisis off on to schools, governors and local authorities. For a start, such children are disproportionately clustered in the poorest areas of the country. I once met a primary teacher who had moved from Hertfordshire to inner London. She told me that she reckoned more than a third of her class in Lambeth would have been diagnosed as having emotional and behavioural difficulties if they had lived in Hertfordshire.
The Government must set up a major initiative aimed at identifying and helping such children. They need an integrated approach involving specially-trained teachers working with social workers, psychologists, youth workers and, of course, the parents.
If the family has housing problems, these should be made a priority. If a parent is mentally ill, alcoholic or a drug abuser, this should be addressed as a matter of urgency - for the sake of the child.
Of course such a focused initiative won't be cheap, but it will be cheaper in the long run than not doing anything. A stitch in time saves nine.