It might be euphoria that makes Oldworth so uninhibitedly forthright in some of his views, but it has to be remembered that had he started work a decade later he might never have been a financial PR man at all.
Oldworth originally wanted a career in motor racing. While he trained at accountancy firm Peat Marwick Mitchell & Co, he spent most weekends competing in the 1978 Dunlop Star of Tomorrow Formula Ford 1600 championship. But in the late seventies, motorsport sponsorship was relatively thin on the ground and Oldworth abandoned his expensive pastime to concentrate on accountancy.
During a subsequent three-year stint at the corporate finance division of NatWest investment bank subsidiary County Bank, Oldworth met Sorrell, who was then finance director of Saatchi & Saatchi. Oldworth also had his first experience of the then 'immature' world of financial PR.
City PROs were 'for entertainment value' and Oldworth remembers how 'you could see the client who was floating his business cringing at the thought of what he was going to have to do to get the coverage'.
Small wonder, then, that Oldworth joined City shop Binns Cornwall with 'no intention of going into financial PR', but as finance director - and, as he puts it, 'to make money'.
Oldworth took over as chief executive of what became Buchanan Communications in 1990 after Binns Cornwall chairman Peter Binns left for The Haggie Company, following a protracted split at the firm over a 26 per cent stake claimed by ADT chairman Michael Ashcroft. Oldworth then inherited a firm with around 50 people and a fee income of £1.5m.
It is a testament to the strength of Oldworth's close relationship with Sorrell that WPP still retains Buchanan after 18 years. The fact that Oldworth is still at Buchanan two years after the end of his earn out arrangement with WPP, though undoubtedly for a handsome incentive deal, is another endorsement of the relationship.
What Oldworth says about this tells you quite a bit about Sorrell and his favourite PR man. 'We come from a similar background - a financial one,' Oldworth says. 'The irony is that most of the financial media would tell you Martin is an accountant, but he never did accountancy. He is the sort of guy who is quite happy to leave that perception out there because it does nothing to harm the financial credibility of what WPP has achieved. He tells it as it is, never overeggs it and is very approachable.'
You can bet that what Oldworth says about himself and Buchanan rings in Sorrell's ears. The contempt with which Oldworth describes 'so-called rainmakers with huge egos who basically destroy businesses' is palpable, and the precision of the technocratic accountant is evident when he talks about Buchanan's role in the City.
'We are not into the bullshit world of spin,' he says. 'Spin in financial PR spells danger. You want a financial PRO who can relate to journalists and analysts and give them a realistic picture of growth prospects. If anyone fails to deliver, the life expectancy of a CEO or CFO is pretty small.'
Given his experience in briefing journalists, his comments appear a little holier than thou. But he prefers to see himself as Sorrell's warm-up man and expresses this as 'getting a journalist up to speed'. And there is no doubt Oldworth means what he says about the dangers of spin and failure to deliver.
A fall in Sorrell's star would be disastrous for the Buchanan boss. Their futures, pasts and presents are after all inextricably linked.
1976: Trainee accountant, Peat Marwick Mitchell & Co
1980: Corporate finance executive, County Bank
1984: Finance director, Binns Cornwall
1990: Chief executive, Buchanan Communications