I have just returned from filming A League Of Their Own in Spain, where I became involved in the tomato-throwing festival in Buñol, in which thousands of people throw thousands of tomatoes at each other for an hour, then spend the next three days being asked why they smell like bruschetta.

My co-presenter Jamie Redknapp posted a photo and more than one person said how disgusting all this was, when there are people starving in the world. I always find this a bizarre argument – one that takes something that your parents used to say to you when you were eight and wouldn’t finish your meal, and uses it to ignore the festival’s cultural history, as well as the huge number of things that are part of our everyday lives and far more abhorrent when it comes to the question of waste.

But my issue, in the end, is not with the argument, but with the level of certainty with which the person expressed it. Social media has exacerbated a trend whereby people speak with complete authority on every subject, regardless of how informed they are.

I recently filmed a travel show in Mongolia, where we got an eagle to hunt a radio-controlled car with a stuffed fox on it, for creative reasons that I don’t want to get into now. But that scene turned out to be the Pied Piper of trolls, and quite a few came out of the woodwork. There were a lot of people complaining about me enforcing my vegan views on people, but that’s fine – I respect their right to do so. What got me was one person telling me that the eagle had probably broken its claw and so would have to be released into the wild, as a result of my cruel “prank”.

The level of inside knowledge this person claimed to have, about something that five people were present to observe, was breathtaking. From their invented starting point, they extrapolated an angry argument, suggesting that it would have been more humane to use a real fox that would have died. But the eagle did not break its claw. I know this because I was there.

On the same show, I went to Colombia and toured the country with the radio host Heisel Mora. While the show was broadcast, a woman tweeted me at various points to inform me that Heisel had not found what I was saying funny, and that she was offended, and that this was why we could never be friends. She knew far more about the week I had spent with Heisel than I did, on the basis of an edited one-hour show.

It has been much documented that we have all become experts, but these social media posts are a sign that people are evolving to a place way beyond expertise. We are entering an age where people can claim to know more about what really happened than the people who were there. Where people will dismiss eyewitness accounts, on the basis of their gut feelings; where they will refute scientific discoveries because the scientist just doesn’t look trustworthy.

Perhaps this was always a logical next step, now that we are living in times when the people we are supposed to trust are doing so little to earn it. But where will all this lead? Evidence will become irrelevant, arguments will become nonsensical and, worst of all, columnists will try to make wild generalisations about societal behaviour based on three social media posts.