When Leslie Evershed-Martin wanted to create a new theatre at Chichester more than 40 years ago, the idea seemed far-fetched.

But thanks to his enthusiasm and that of others, the improbable target was reached. He called it the impossible dream.

It was really remarkable that a small cathedral city such as Chichester should have its own magnificent festival theatre and that it should have survived and expanded with little outside help.

This part of the county abounds in similar unlikely success stories. It took the wealth and eccentric ideals of Edward James to create a foundation and glorious gardens a few miles north at West Dean.

There have also been triumphs at Goodwood, including the restoration of the house, the upgrading of the racecourse, the reinstatement of the motor racing track and now the production of Rolls-Royce cars there.

An earlier unlikely artistic achievement was achieved by John Christie at Glyndebourne. The notion that you could attract a lot of opera buffs to a remote country house in Sussex and charge them high prices for it must have seemed faintly barmy even before the Second World War.

But Glyndebourne has survived and prospered to emerge with one of the best new buildings in Sussex and a programme enjoyed by the poor as well as the wealthy.

Equally, the odds must have been stacked against Jonathan Minns when he proposed to transform an old pumping station in Hove into a steam museum 20 years ago.

It was done without help from the National Lottery or aid from Europe, which has assisted many more recent projects. Yet the British Engineerium remains a tribute to his tenacity or sheer bloody-mindedness.

Perhaps the most remarkable example of an individual succeeding with a single idea was Henry Cohen, a small-time garage proprietor, in Brighton. He put forward a proposal to create a purpose-built harbour along a coastline which had none.

Others had nourished similar notions for years before but none had had the pertinacity to pursue them.

The Brighton Marina scheme had to get through town polls, town meetings, Acts of Parliament and overcome implacable opponents, such as Tory councillor Danny Sheldon and Labour MP Hector Hughes.

When it surmounted all these difficulties, the project still had to ride through one of the longest public inquiries held in Britain.

Building the harbour in one of the most exposed positions in Europe was a huge technical triumph.

There were also problems with the council's insistence that the harbour walls be built before any onshore development, which meant £50 million had to be committed to the enterprise before a penny was received in return.

The original investors all lost a lot of money and the marina seemed doomed to become a white elephant before George Walker made a shrewd offer to buy it at a knock-down price, quickly recouping his money through audacious deals. It has been left to local businessman Andrew Goodall to complete the development.

None of these men of drive and enterprise did it mainly for money. I doubt if Henry Cohen ever made much out of the project, which proved to be one of the biggest schemes in Brighton of the last century.

What they all had was an unshakeable faith and the ability to persuade others to go along with them. They possessed a strange, reckless drive that enabled them to overcome obstacles others would have found insuperable.

Are there many men and women in Sussex today with great ideas, a glint in their eyes and the panache to drive them forward?

I believe there are and that we are in an age more entrepreneurial than any since the Victorian era. More on impossible dreams next week.