Now, he could be sitting on a fortune. But it took some grit to realise his dream of turning his experience into a business. He had such belief in himself that he quit his job as a PE and maths teacher at an independent school in London to run the business full-time in September.
He has drummed up pound;145,000 of investment in return for giving away 45 per cent of the business, sometimes using slightly audacious tactics. "A friend of mine went on a stag do, which was paid for by one guy. I found out who he was and pitched my idea. He brought two friends from the same office to watch and they all liked it. Banks are very risk-averse. You've got to find people who are open to a gamble."
Chris Mayo is also glad she stuck to her guns after putting her big idea to the hard-faced panel of BBC2's Dragons' Den to be told her brightly-coloured resources for primary pupils were pointless and unworkable.
The outgoing, talkative 54-year-old former primary teacher from Kingston-upon-Thames, London, was not fazed by the experience. "I believe there's a big market for my products out there," she says. Chris quit her job 11 years ago to go into business after a lesson teaching Year 2 pupils maths using sweets gave her the idea for "sweet counter"; coloured images of jars and boxes of confectionery aimed at teaching children about hundreds, tens and units. Now she sells more than 100 different products via the Sweet Counter website, which made a turnover of pound;203,000 last year, with pound;96,000 profit.
Little more than a decade ago, Chris was one of the hundreds of teachers who dream of setting up their own company. The key to success, she believes, is time and money. She spent pound;6,000 producing her first batch of resources (a pound;3,000 bank loan plus pound;3,000 savings) and several years doing supply work while she toured exhibitions drumming up business.
Despite the mauling she received on Dragons' Den, Chris is certain she is destined for success. The Dragons accused her products of unoriginality, saying anyone could make them. "But it's like ready-made meals," says Chris. "Teachers don't have the time to make these things anymore because of targets and paperwork."
She said she made the decision to go on Dragons' Den at 1am on a whim and 10 days later, found herself in the studio. "The upside was the publicity, the downside was losing my dignity. I could tell I'd lost them after about 10 seconds from the look on their faces; they were growling," she says. "I didn't want to watch the show, but the general consensus from friends was that I scrubbed up well and didn't look too fat. They do say television adds pounds."
Now Chris is happy to be working independently. "At the start I thought a big company would take it on and make me loads of money. But I don't think anyone could do it as well as me," she says.
Perseverance is a key characteristic of any entrepreneur, as Elaine Stephen, 43, inventor of the Walkodile, a snake-like length of handles and straps that ensures primary children can move about safely on school trips, knows well. She has won a string of awards for her invention since coming up with the idea in 2002 - including the European Women's Award 2007 and most recently Nursery Innovator of the Year from Nursery Management Today. She spent pound;125,000, mostly of her own money, seeing the Walkodile (featured in The TES Magazine earlier this year) to completion, re-mortgaging the house, selling a second property and shares. She raised pound;25,000 from the local council and Shell; the patenting process alone cost around pound;50,000.
The turnover of around pound;150,000 since 2005 has mostly been ploughed back into the business and Elaine still works as a full-time teacher at Buchanhaven Primary School in Peterhead, Aberdeenshire. "You have Paula Radcliffe days when you think: 'What am I doing?' and Kelly Holmes days when you're really high," she says.
Many teachers choose to work part-time while they launch their business. Mike Mills, 35, an achievement co-ordinator (similar to a Head of Year) at Arthur Terry School in Sutton Coldfield, Birmingham, set up his teacher training company after his experiences leading a team of 10 staff sparked an interest in helping teachers progress in their careers. He set up his business Excellence in Education for about pound;5,000 in September.
Mike leads a small team of two trainers delivering courses such as "21st Century Team Leadership" and "OK to Outstanding: winning ways to transform the way you teach". "We just want to deliver what really matters," he says.
Helen Pengelly, 44, a former maths teacher from Worthing, left her job two years ago to set up business as a food wholesaler aimed at allergy sufferers, called Johnson's Dietary Provisions.
She got the idea after discovering she had coeliac disease and had to avoid gluten. Helen spent pound;75,000 setting up the company (including pound;50,000 from re-mortgaging and a pound;25,000 bank loan). The first year's turnover was pound;30,000 so she has yet to break even. "I'm talking to some potential investors and I'm looking at setting up a network of distributors and a retail unit in Brighton. If I knew then what I know now, I would have found an investor at the beginning, as it would have saved me a lot of loan interest."
Setting up your own business isn't easy. The key is to research the market, finding out about the strengths and weaknesses of your competitors, as well as drawing up a careful business plan. And of course, it helps to have a killer idea. The education publishing sector alone is worth pound;1,409 million a year, and education equipment pound;535 million. So being a teacher with a wealth of experience in the classroom, the inspiration could be right under your nose.
James Dyson is a British industrial designer and inventor of a vacuum cleaner. His net worth is said to be more than pound;1 billion.
"The exciting bit of business is what I first set out to do: make something work better. It took thousands of prototypes, years and disheartening knock-backs from 'big business' until I achieved what conventionally people refer to as success.
"Failure too often gets swept under the carpet, but it's an important part of business. Understanding why something hasn't worked is the thing that spurs you on.
"Don't be confined by rules. If you are to make a success of your idea, being different is an asset. Set-backs will help define a new direction and strengthen your determination to succeed.
"Hindsight has taught me a few things. If you can, do it yourself. I spent too long seeking a licensing deal. I wish I'd had the conviction to go out on my own right from the start.
Don't forget to protect your ideas. Good ideas will keep you ahead of the pack. And do not be obsessive about market research.
Market research cannot tell you whether the public will buy something that they hadn't imagined.
"It told me no one would like a clear bin on a vacuum cleaner. But people tell me seeing the dust and dirt they have sucked up gives them satisfaction."