A philosophy degree at Bristol University followed. Then Mr Opik headed for the North-east to join Proctor & Gamble, where he rose swiftly to become the detergent giant's global personnel training manager - a lengthy job description which he hopes to exchange for the letters MP on 1 May.
"You can't grow up in a family so affected by politics as mine without wanting to right wrong," he says.
He won the nomination against stiff opposition last September when Alex Carlile announced he would stand down after 14 years at Westminster. Except for a blip in 1979, when the Tories unexpectedly captured the seat, Montgomeryshire has been Liberal territory for more than a century.
Mr Carlile leaves behind a majority of more than 5,000 over the Tories, sufficient, it seems, to see Mr Opik home. But no chances are being taken. "Paddy's been here twice and David [Sir David Steel] once," the energetic Mr Opik said as he strode round Tan Yr Allt, a 1960s estate contrasting sharply with the timber-framed black-and-white houses that dot Llanidloes.
The Rev Penny Burkill, who looks after half a dozen Methodist congregations, was impressed: "He's the sort of person who will represent us well - he's very sincere," she said.
Back in town, Mr Opik expanded on one of his favourite pastimes - motorcycling. He bumped into Simon Evans, about to ride off on a gleaming 750cc machine to his job as a computer operator in Newtown, 10 miles away. "I own two," Mr Opik remarked modestly, as a discussion on stopping distances and fuel consumption got under way. Transport is a problem for Owen Jarman, a 72-year-old retired farmer visiting Llanidloes from his remote mountain home. "We have a post bus and let's hope the Post Office isn't privatised," he said. Mr Opik nodded vigorously.
Trays of meats ranging from prime steak to pig's liver are displayed at Edward Hamer's shop, underlining Mid-Wales's dependence on pastoral farming.
BSE is much talked about. The Tory candidate, a farmer, Glyn Davies, has had six cases in his herd. "I well understand how much of a shock BSE has been," he says. The latest European Union rebuff to Britain is not exactly helpful to the Tory cause.
Labour, third in 1992, is fielding Angharad Davies, a 25-year-old political researcher regarded as a rising star.
Helen Jones, of Plaid Cymru, the Green Party's Sue Walker, and John Bufton, of the Referendum Party are striving to make an impact but without much success.
Mr Opik is refreshingly open. "I have a 70 per cent chance of winning, the Tories a 30 per cent chance," he says. A man of many parts, he claims to have loved flying ever since falling out of a tree when he was seven. He holds a pilot's licence, paraglides and is an amateur astronomer.
Vote of confidence: Lembit Opik, campaigning in Montgomeryshire, hopes for an easy win in this traditionally Liberal seat, but is taking nothing for granted
Photograph: John Voos