"I had two ambitions when I was younger - one was to be a teacher and the other was to be a presenter," recalls Suzanne Hills. "I'm lucky to say at the age of 30 I've achieved both those goals."

Having carved out a successful career in the cut-throat media world as a television presenter and science correspondent, Miss Hills gave it all up to teach science at Cheney School in Headington, Oxford.

But what would persuade someone to give up a glamorous, high-paid job to teach in a secondary school?

If a recent study commissioned by the Training and Development Agency for Schools (TDA), is to be believed, it is because teachers enjoy more "natural highs" than people in comparable careers and break into a smile on average 10 times every half hour.

Miss Hills, who took part in the research, was not surprised by its findings.

She did a post-graduate teaching qualification in 1996 after finishing university, but some part-time work for Oxford radio station Oxygen led her to being offered a full-time job at ITN and she "didn't look back for a long time", progressing to various prestigious presenting roles.

It was only after a few years, when her show was watered down from a science programme to looking at computer games, that she began to question what she was doing.

"I was struggling to find the worthiness in it. I needed soul food. I went freelance. It paid really well, but it also gave me some extra time, so I went back to teaching part-time.

I came to Cheney and loved it. I started looking forward to the days when I would be teaching more than the television work. It surprised me. Even though the teacher's salary is a lot lower, I have a better quality of life and I feel as if I'm giving a part of myself to the job.

"I have to say I haven't looked back. I love my job. I don't miss the money. That wasn't a good enough reason to stay.

"Working in television was a really good experience. I travelled all over the world, interviewed some really exciting people. The training in teaching made me a good presenter.

"Being a presenter taught me how to capture an audience and keep it, using various different methods to express and explain something.

"It has provided me with a bit more to share with the kids about the outside world.

"They enjoy hearing about it and they like the fact that they think some gave up what they perceive as a glamorous career to come and teach them.

"If I didn't have teaching a bit of me would die. There are always kids who are vulnerable and you get to feel you are making a difference. I get to be myself completely in front of these kids, sharing something with them every day. I go home exhausted, but in a good way."