The point was that using such phrases in front of the kids nurtures in them the habit of making highly incontestable statements requiring lots of disclaimers the kids can't think of, because they don't know enough stuff, and that's OK for them. The point was that I, personally, learned names for some (biological) concepts long after I was presented with the 'meat' of them, and I don't know if it is a good thing. But whatever, lichens are very interesting, too.