Ageism, like sexism, is a scourge of our times. However you dress it up, the automatic assumption that youth equals freshness and vigour, while age equals tiredness and inability to change - is discrimination.
As long as there are schools which advertise, as one Essex school did recently, for deputy heads aged between 30 and 36, or something similar, there will always be cause for legitimate complaint. So we welcome the arrival of the Association of Teachers Against Ageism. But there are other reasons why mature students are often rejected by schools. The most obvious is that experience does not come cheap. When money is tight, heads are always likely to choose the cheaper recent graduate over the older candidate.
Another problem is that some colleges are turning out more teachers than the local schools need, leaving those unable to move - frequently mature students with family commitments - chasing too few jobs.
Perhaps the time has come to establish the link between supply and local demand. If schools were encouraged to recruit trainees and enter into a contract with the college of their choice to help train them, there would be fewer people disappointed - and fewer claiming discrimination.