The pace of change is quite astounding. No one will return failing to realise that China, not America, is the future. Many schools already have links with China, and those that haven't will find a ready audience for all kinds of contacts between pupils and teachers. They are avid to learn from us and, language problems notwithstanding, to communicate (why not start Mandarin as an optional subject, or go one further, as Brighton college has done, and make it compulsory for all pupils?) I was in Beijing for two days, along with 100 senior principals from around the world, to attend the G100 conference, sponsored by HSBC and organised by iNet, with the theme "Transformation and Innovation". A revolution has occurred in schools worldwide in the past 10 years, and I realised just how far they have been co-operating via the internet and in exchanges. What was unusual about this conference was not only the breadth of countries represented but also the near unanimity on many points. I would like to share three of these with you.
The benefits of inclusivity proved a common theme. Empirical evidence and anecdotal comment showed that creaming off able pupils does not benefit children overall. Schools which separate children along religious or racial lines were seen not to be contributing responsibly to social harmony by not allowing young people fully to develop an understanding of other cultures.
There was a strong sense that if global citizenship and respect for diversity are not taught at schools, children - and therefore the future - will be the losers.
No surprises there, perhaps. But there are powerful lessons for faith schools in Britain, where the general good suffers for a (questionable) added benefit for the few. There are also messages for fee-paying schools such as my own.
Widespread antipathy was registered for over-reliance on testing as the only means of evaluating the performance of pupils and schools. There was a general recognition that tests can only ever assess a very limited aspect of a child's contribution and abilities, and that the obsession with testing might be in the interest of governments, political parties and school districts competing for funds, but it is not in the interest of schools themselves, or indeed children.
Education for the whole child was overwhelmingly supported - including, encouragingly, the need to consider, and even teach, happiness (which really can be taught, in the form of well-being classes).
A third powerful message concerned the benefits of collaboration - as opposed to the competition between schools which characterised the thinking of the 1980s and 1990s. Head after head spoke about the benefit of sharing best practice between groups and nations. It is clear that the 21st century will be very different, whether a school is on the Isle of Skye or in rural Gwent, or in the Amazon Basin. The opportunities to learn from others and collaborate are bountiful, and schools ignore them at their own peril.
My hope is that this pioneering conference will be the first of many to build a new model of schooling in the 21st century - worries about global warming through increased air travel notwithstanding.
Anthony Seldon is master of Wellington college, in Berkshire