Teaching Mandarin makes wonderful headlines and is often met with initial enthusiasm. But afterwards? First, it is extraordinarily hard to find good teachers of the language. Second, it is a very difficult language and those best at it are often the musically gifted, not those with a perceived talent in modern languages. Third, just as the banjo is very easy to play badly, so is Mandarin very easy to speak badly. I was in China when a well-meaning English exchange teacher accidentally accused the local Chinese mayor of being something unpleasant on a pig's body. A diplomatic incident was averted only because most local people seemed to think it was a fair judgment.
Every Chinese person I have met pleads for the English to use decent translators, and not conduct complex negotiations in a language that foreigners can take years to master. Fourth, we risk putting many pupils through a gruelling experience that they will never use, even on holiday.
Fifth, anecdotal evidence suggests high fall-out from mass schemes, bringing the danger of a negative and hostile counter-culture against a language of great international importance. Rather than embark on mass conscription, we should offer a few taster classes to select pupils with the ability to learn Mandarin and then teach them.
As for happiness, you can no more condemn it than you can condemn goodness, which is a big help to those who put it forward as a curricular subject.
This bandwagon received a major boost when a study from the United Nations children's fund (Unicef) found that children in the UK are the unhappiest in Europe.
The problems with teaching happiness are not obvious ones, such as the fact that you cannot define it, or that there is an argument that unhappiness can be a driving force that motivates humans to better themselves. The real problem is that by ramming happiness into an already crowded curriculum, you exclude much more crucial subjects.
Two new "subjects" cry out to be included (and might, by the way, add to the sum of human happiness): risk-taking and risk management. We have taken too much risk out of children's lives, yet managing risk is a core life skill. If we do not introduce children to risk in a managed and caring way, they will inject it into their own lives, sometimes quite literally.
We have removed risk from schools by selling off school playing fields and making school sport unfashionable. There is a risk of losing in sport, a risk in performing musically or in a play, while music and drama have been savagely cut back. There is a risk in sending pupils out to do community action in disadvantaged areas and a massive incentive for teachers not to take children up mountains or down rivers for fear of legal action if things go wrong.
Yet I have seen more happiness created by a child's experience of sport, music, drama and outdoor pursuits than I will ever find in a timetabled lesson on happiness. That is why the teaching of happiness is at best a fashionable diversion, at worst something that takes resources away from what matters.
The other item we need to include in our curriculum is team membership. All humans have to play in teams in their lives, and a street gang is dangerously close to being the fall-back setting for children who need to feel the closeness that being in a team can bring. You learn about playing for a team by being in one - in sport, an orchestra, acting in a play and so on.
Of course, we can treat our curriculum in the way we treat rock stars - grab the superficially attractive, fete them for a while and then drop them for the next latest thing - or we can base our curriculum on core life skills.
Dr Martin Stephen is high master of St Paul's school in London