Nearly always we know more than we think we know. Indeed, the overwhelming problem in the internet age is the availability of too much information rather than too little. And yet our appetite for more on topics when we already know enough is apparently insatiable.

Take the furore over the Attorney-General's decision not to publish letters from Prince Charles to ministers in the last Labour government, the latest example of a wider paranoia about information and its availability. Publication would do no more than confirm what we know already. The explanation from Dominic Grieve, the Attorney-General, was itself a stark confirmation that the Prince has strongly held opinions that he expressed to Tony Blair and other ministers. He explained that the Prince's "particularly frank" views could cast doubt on his political neutrality. It was in the national interest to ban publication "because if he forfeits his position of political neutrality as heir to the throne, he cannot easily recover it when he is king".

Grieve's verdict serves to reinforce the scale of the forfeiture, a candid admission that publication would expose the Prince as someone who on various issues cannot resist aligning himself with one side rather than the other. Those views have been public for years, on farming, hunting, architecture and environmental policies. Alastair Campbell's diaries imply that the Prince's allies might have leaked a letter from him to Tony Blair in which he wrote that if the government banned hunting, he might as well go skiing all year round. It appeared in The Mail on Sunday. Campbell quotes Blair noting that Charles had been captured by a "few very right-wing people". Blair knew a thing or two about right-wing people and was happy to hang around with a few himself, so the Prince's friends must have been very right wing indeed to provoke such an observation.

Blair's best-selling memoir was explicit about Charles's intervention in relation to the hunting ban: "He thought the ban was absurd and raised the issue with me in a slightly pained way." More widely, Blair noted: "Prince Charles truly knew the farming community and felt we didn't understand it." In a typical Blair-like twist, these minor revelations were no act of anti-establishment insurrection. Blair made clear he agreed with the Prince on hunting and thought he had a point in relation to his government's failure to understand farming. Blair revealed the Prince's lobbying against government policy while agreeing with the Prince. The most revealing part was how relatively relaxed Blair was about persistent princely interventions, not just because he agreed with them.

But a Prince obliged constitutionally to be impartial is powerless in the end to shape public opinion compared with newspapers and the rest. The Prince's revenge did not take the form of policy triumphs but in the fact that neither Blair nor Gordon Brown were invited to his son's wedding last year, a puny but harmless act of spite. Again, we know what happened. We saw it – the other former Tory PMs rolling up for the big day and the two out of power Labour PMs nowhere to be seen.

What we do not know is whether the Queen clings on in post because of concerns about her elder son's suitability, but we never will and some of us do not care. The publication of his letters to ministers would not answer that one.

Yet in this anti-politics era there is a widespread assumption that information is always malevolently suppressed and we all wander around in a state of manipulated ignorance. There was something about the over-excitement of the WikiLeaks' "revelations" that suggested the act of defiant publication conferred breathtaking significance on the substance of the documents. Frankly, a lot of them were unsurprising.

Meanwhile, we ignore what is in front of our eyes. The Charles affair is relatively trivial. What he thinks and does is of little practical significance. But one of the more striking dimensions of the Savile affair is how much was already out in public, not just in relation to him but others, too. I recall Louis Theroux asking Savile about rumours of paedophilia during his documentary. How did he have the confidence to pose the question? On what were the rumours based? I ask the questions now and yet did not do so at the time. Newspapers yesterday reported that John Simpson's memoir contained a passage about a BBC household name from decades ago who abused children. Only now does a section from a widely publicised memoir that has been around for years become a news story.

I doubt even if the unpublished texts and emails from David Cameron to Rebekah Brooks were published we would know much more than we do already. Instead, there is a danger we forget what we do know in getting too worked up about what we do not, from the emails of Jeremy Hunt's former adviser when he was Culture Secretary to the horrifying testimonies from those who had lives wrecked through the activities of some out-of-control newspapers. I would love to read the Cameron emails, but we already know the level of social intimacy between him and Brooks and the context in relation to the BSkyB bid.

The late Peter Jenkins, the brilliant columnist for The Independent in the era when only a few mighty writers performed the task, suggested that his job was to make sense of the "torrent" of haphazard information available. He was writing in 1970, long before the internet and an expanded media. We must always be alert to the self-interested suppression of information but the bigger worry, from Prince Charles to Savile and on to hacking, is that we fail to reflect and act on what we already know.

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