For Kate Stanley life really did begin at the age of 40 - she became a teacher. Kate, a former education liaison officer, has been working at Chestnut Lane County First School in Amersham since September and loving every minute. Stephen Mackay, a chartered engineer for 13 years, made the same mid-career change decision and has swapped drawing board for blackboard.
Kate and Stephen are just two of a growing number of mature people who have chosen to go into teaching, bringing with them a wealth of experience. Their decision flies in the face of George Bernard Shaw's observation that "He who can does. He who cannot teaches".
Both Kate and Stephen admit that for years they were frustrated teachers - but a mid-career change can be difficult.
"Friends will do anything to put you off," observes 36-year-old Stephen, whose route into teaching at Edgware School in Barnet was mapped out by redundancy. "Somebody even commented that I must be either very brave or stupid."
It is also a move that can leave you financially worse off.
"Nobody should go into teaching to get rich," says Kate, who took her PGCE at Hertfordshire University after a career break to start a family.
Many mature teachers feel undervalued when schools refuse to adjust their salary according to their work experience. They claim they are often advised to either take the job or leave it and they often feel too intimidated to pursue the matter.
"Don't make salary a priority," Kate urges fellow "oldies" entering the profession. "It will give the impression that is all you are worried about.
"Don't go into a job expecting anything more than the basic newly qualified salary. If you get any more that really is a bonus."
But Stephen, who teaches design and technology, believes that if newly qualified teachers have the experience, they should hold out for what they think they are worth. He stood his ground and with polite negotiation was able to agree on something in the middle.
Few schools can afford the mature entrant and the thirty-somethings often find themselves on the lowest rung of the ladder. In addition mature entrants claim they face hostility from governors and headteachers, who are suspicious of their motives for starting so late - are they working to pay the school fees or just to finance luxury holidays?
"I used to feel apologetic about my age," says Kate. "And often found myself beginning every sentence with: 'Sorry I'm 40.' But you have to try to see your age as something extra you are bringing to the job and not something that detracts from it."
The first hurdle for an older entrant is securing a job which, in some cases, can take a long time.
Kate and Stephen are under no illusions about their luck in getting employment soon after finishing their PGCE course. Stephen was beginning to think he had backed the wrong horse when after 13 applications he hadn't had any interviews. "I had literally just finished discussing with a careers adviser how else I could use my teaching qualifications, when I received the first of only two replies." Kate is certain that if she had not done teaching practice at Chestnut Lane and subsequently been offered a part-time job, she would be out on her own.
But mature entrants may try to sell themselves too hard at interviews, knowing that they could be expensive.
In order to prove they were willing and not set in their ways Kate and Stephen say they often found themselves volunteering to do after-school activities.
"The problem is, when you really want a job you can find yourself promising the earth," says Kate. "At one interview I heard myself agreeing to take full control of the netball team. With hindsight, I'm glad I didn't get the job, because I wouldn't have been able to cope with all that and my family responsibilities as well."
They both say the hardest part for mature new teachers can be lack of advice offered by the school, but they understand many schools have a mentoring system.
Kate, who has a mentor at Chestnut Lane, urges other mature students to ask for a mentor.
She says support in the the first year is vital and adds: "My mentor is considerably younger than I am so it's quite interesting when we attend meetings together as mentor and new teacher because of the age difference.
"As we walk in you can see people thinking that she is the new teacher and that I am the mentor. But I don't feel embarrassed because it still comes down to teaching experience.
"Even though she is quite a lot younger, she has notched up five years of teaching experience, which I very much respect, and I hope that she respects my experience as well."
Kate advises new teachers not to be afraid to ask for help. "You get this feeling that because you are older, people expect you to be able to automatically manage juggling a family and a job. But a lot of the difficulties you might have when you are newly qualified are the same whatever age you are."
Both Kate and Stephen have so far found teaching to be a very different experience from what they imagined.
While they were prepared to recognise the limitations of their courses, the extent to which they were unprepared for the responsibility involved in having the life of a group of youngsters in their hands, was frightening. "Let's say the idealistic things that drove me into teaching haven't gone out of the window, they're kind of on the ledge," says Kate.
"When you get down to the practicalities of teaching a class of five-year-olds, it's quite difficult to keep in mind all the theories about how children learn and all the things that inspired you to be a teacher."