What is the magic ingredient that keeps some teachers keen after decades in the classroom? It’s a question that could become increasingly important as the Government’s pensions plans make retirement before the age of 65 a rarity rather than the choice for half of all teachers.

So, for all those new, young teachers taking up the chalk, learn a lesson from your older, more mature colleagues, and the rest of your career - and your life - could be a pleasure.

Such teachers may come from primary or secondary schools, idyllic country towns or tough inner cities, but they will have much in common: their heads will consider them excellent teachers, and they will still enjoy what they do. Although many will have been in one school for years, they tend to reinvent themselves to stay interested - and interesting.

Barry Hunt, 54, has taught English at St Mary Redcliffe and Temple secondary in Bristol for more than 30 years.Over that time he has had a variety of roles, including a spell as acting head and another as deputy head of house; he even taught law for a while. “Nothing has remained the same,” he says.

Helen Dagnall, 52, a modern languages teacher from Bishop’s Castle community college in Shropshire, says: “It’s important to make the classroom a happy learning environment. The time should pass quickly for pupils, but they should always learn something and come out thinking, ‘That was good’.”

Mature teachers have dealt with the gamut of challenging situations, they are good at prioritising, understand the short-cuts, and know who to call when they need help. They often don’t seek promotion and therefore have no reason to impress line managers. “I speak my mind at meetings - I ask why - otherwise I won’t do anything I do not agree with,” says Gill Peregrine, 54, a maths teacher at St Mary Redcliffe.

Bob Smith, 52, who teaches humanities at South Camden community school, London borough of Camden, says: “Every school needs a Mr Chips. I’ve never seen a reason to change, and I’ve never chased promotion.”

Martin Spiller, 50, who teaches classical civilisation at St Mary Redcliffe, is “a classroom bloke - I don’t crave responsibilities”.

It’s not lack of encouragement that stops them going for promotion; most are not interested. The experience of 53-year-old Catherine Mitchinson, a science teacher at South Camden, is typical. “Every line manager I’ve had encouraged me to go for promotion, made me think I could do it. But I never felt my job here was finished. I always felt there was more to do and more I wanted to try out.”

Support from colleagues and managers is vital to job satisfaction; working with and learning from colleagues is a pleasure. In spite of the pressures, school can be an enjoyable place to be. As Ms Mitchinson says:“Many of the days I’ve earned my money, it’s been a great pleasure.”

Lifestyles vary. For some, school takes up most of their waking time. Ian Swann, 50, a teacher at Grangetown primary school in Sunderland, says: “I don’t have a social life outside school; it has taken up most of my life.”

But others spend their free time doing activities that have nothing to do with teaching.

All the teachers and their heads say it is important to have older staff members - they are loyal, provide living examples of good practice, offer continuity for pupils and the community, and act as role models for young teachers. As one head says: “They stop younger staff getting too intense, and make them realise it’s not just about setting targets.”

So what top tips do the golden generation have for those just starting out?

In the classroom

* Like your pupils

* Be someone they can respect

* Don’t try to be their best friend

* Get to know them

* Have high expectations

* Have fun

* Have a clear understanding of what is acceptable and what is not

* Sort out discipline first

* Be consistent in what you do

* Get involved in extracurricular activities

* Cultivate a good presence in class

* Pass on your enthusiasm

* Be prepared to work hard

* Don’t get angry - but act it when necessary

* Teach children how to learn

* Explore a variety of ways of teaching each topic or lesson

* Remember children learn in their own way Outside the classroom

* Be your own person

* Be able to switch off

* Accept that anyone can have an awful lesson

* Don’t be weighed down by failures

* Have interests outside school

* Don’t be bullied. Stand up for yourself and what you believe in Remember, you came into the job because you want to work with children - make them your priority.