You may be surprised to hear that, when writing columns, I try, if at all possible, to avoid venturing opinions. If at all possible, I hasten to repeat (which is another of my column-writing techniques). I realise the job necessitates a certain amount of opinion-venturing – it's a good week for me if I get through the thousand words conceding only one or two. But, if I can avoid any more, I will.

Illustration by David Foldvari.

This wasn't always the case. When I started writing in this newspaper, I sprayed my views around with the innocent joy of a toddler who's yet to contemplate the possibility of not being loved, and as if they came from a source as bottomless as the water table. But I soon realised that I was simultaneously using up a finite resource and randomly annoying articulate interest groups more effectively than a Home Counties fracker. And mine is not the sort of gas that keeps anyone warm.

I don't think I have particularly weird or extreme opinions – on good days, I reckon I come across as pretty reasonable. And that's the key to the problem: I seem reasonable and most people think of themselves as reasonable. Before I opine, they would probably presume I was in agreement with them. But, if I open my mouth, they may find otherwise. Every time I say something I think, a new swath of well-disposed readers have their assumption or hope that I thought as they did swept away.

Lots of people – maybe most people – are broad-minded enough not to dismiss someone just because he or she has said one thing with which they disagree. But, as an attitude to life, I wouldn't say that approach was on the rise in the current climate. To the many raised and furious voices of the internet, straying from their view of whatever thing they're monomaniacally obsessed with is heresy. In that context, agreeing to differ about a medium-sized issue counts as quite a sophisticated approach to life. A bit permissive, even. It smacks of the impure.

I'm not the only one to have noticed this. Most politicians definitely have. Their job is ostensibly even more about the purveying of opinions than columnists', but these days they obsessively save their views for special occasions. Rather than risk alienating anyone at all, the current strategy for political success is to be serially photographed in mundane settings – pubs, cafes, high streets, etc – in the hope of seeming reasonable, and then issue bland statements saying you're concerned about something concerning. Clues about what they really reckon are barely more forthcoming than they are from the Queen – and much less so than from Prince Charles.

So I was surprised, and heartened, by two opinions that were voiced last week by people who didn't really need to. One was Richard Dawkins, who's already very much on record with one personal opinion, so I thought he was really spoiling us when he apparently said, at the Cheltenham science festival, that fairytales and believing in Father Christmas were bad for children. For those of us who seek to take the mickey out of him, this could hardly have been more fun if we'd scripted it. "There is a God!" I thought.

But, according to Dawkins, I was wrong. The next day, he killed the joy as usual, condemning the media for twisting his words. "I did not, and will not, condemn fairytales," he insisted. He accepted he'd said that it was "rather pernicious to inculcate into a child a view of the world which includes supernaturalism" but then clarified: "The question is whether fairy stories actually do that and I'm now thinking they probably don't." Smashing. Just when the poor media think they've winkled a genuine opinion out of someone, it disappears like so much fairy dust.

However, the other of the week's opinions was even more surprising. It came from Royal Mail and it concerned fish stocks. The Mail is issuing a 10-stamp set depicting various species of fish. Five of the stamps are marked "SUSTAINABLE" – the herring, red gurnard, dab, pouting and Cornish sardine – and the other five "THREATENED" – the spiny dogfish, wolffish, sturgeon, conger eel and the (presumably now not so) common skate.

Where's the opinion here? you may ask. Aren't these just informative facts? It depends on your definition of a fact. One definition might be: "something that may be asserted on BBC News without their having to balance it out by giving broadcasting room to someone who will assert the contrary". By that definition, of course, it isn't a fact that the MMR jab has no link to autism, so I suspect that what the Royal Mail is implying is perfectly true. But the National Federation of Fishermen's Organisations considers it arguable at best. And thinks it an argument Royal Mail should have kept out of.

I'm glad, but also amazed, that it didn't. It's been privatised – it has no obligation to the public good, and will gain nothing by changing people's fish-eating habits. And it's not as if, had the fish stamps not all been marked "SUSTAINABLE" or "THREATENED", anyone would have called for Royal Mail to 'get off the bloody fence' about the sustainability of fish stocks. Try as I might, I find it difficult to avoid the conclusion that someone took this inevitably divisive decision purely because they thought it was a good thing to do. Bravo.

It's obviously also a worrying development. Now a precedent has been set that stamps can express an opinion, who's to say that future views will be so noble, or expressed for such (as far as I can tell) unimpeachable motives? Will there be advertising on stamps? Or, more plausibly, and also more insidiously, will they become the equivalent of those newspaper reports that are generated by a press release about a corporation-sponsored survey? Maybe a manufacturer of Red Gurnard Bites has yet to emerge from behind this initiative?

Even if the views remain sincere, that doesn't mean they'll stay apolitical. If you make your living from commercial fishing, I suspect you'd say that Rubicon has already been crossed. Who will be editorially responsible for the stamps' content? A journalist? A regulator? A respected intellectual like Richard Dawkins?

That would make for a cheery Christmas issue: a painting of some children sledging with "SUSTAINABLE" written across it; a choir of angels marked "A PERNICIOUS LIE"; and a jolly Santa captioned "A LIE – BUT PROBABLY NOT PERNICIOUS". I'm not going to tell you what I think about that.