I love those purple blobs. Fantastic Voyage was on television recently - a sci-fi Sixties classic. A group of scientists gets shrunk and injected into an important person so that they can operate on his important brain.
"Everything on this craft is nuclear-powered - except for your wireless."
Well, that's all right, then.
It's 1966, so the inside of the human body is an enormous lava lamp. But I was eight when I first saw the film and it blew my mind. Right through from the floaty blood to the spangly brain. I never forgot what antibodies were, nor what they tried to do to Raquel Welch.
Poor Raquel gets chased, wrapped and throttled by shredded rubber. And someone else has a very bleak encounter with a giant piece of cotton wool.
Now, if I were a science teacher, I'd whack that on my interactive whiteboard and quiz the kids about blood. "Look at these blobs. What do you think they're for?" Another generation of children would have exciting purple dreams about the battles going on inside them. And grow up to wreck the colour scheme of their parents' house.
Result. I start every lesson wanting it to be a fantastic voyage. Too often I finish it limping for the exit, just grateful no one drowned. But like many teachers, I'm still hooked on the notion that if I could just find the right way to present the topic or the task, I'd see tears of life-altering joy in their astonished eyes. And it should be possible. After all, today's classroom technology has a bit more to offer us than the nuclear-free wireless.
So I thought, hey, this is cheery stuff, when I read about how many teachers and pupils love interactive whiteboards. I'll admit that I've never forgiven those things for making my handwriting look like Guy Fawkes's signature. But lots of teachers swear by them now, and most of those questioned in a recent study praised their effect on "flexibility and motivation". Flexibility? How often do you hear teachers use that word about something the Government wants?
It's both tempting and fun to sneer at these findings, though. These shiny, happy things are making lessons more exciting but they're not improving results. Nyergh, nyergh, told you so, we can scoff if we want to. Let them all suffer in the classroom and then go out and play with rocks and sticks like we had to. All we had in my day was one slate for the whole village.
If we were lucky, moan, grumble.
But wait. If the results are no better with interactive whiteboards, at least they're no worse. And if the final destination is the same but everyone had a better time getting there, that's worth something. I'm almost ready to buy myself a lava lamp to celebrate.
Almost, but not quite. One comment from a headteacher has lodged in my mind, like a tiny scientist performing surgery on my brain. "The boards are a great way of making modern languages fast and visual. When you do weather and say nuage you can show a moving cloud."
Yes, you can. Or you can point at the sky. Look, I am cheered by the good news about these boards. Whatever boosts pupils' motivation also protects the sanity of teachers. So I'm not against a multi-media approach to making lessons more groovy.
But real things are fun, too. In fact, today's kids take in so much of the world through the media that reality could just be the new rock 'n' roll. I once took a small Year 9 group outside for a Shakespeare lesson. They took their chosen speeches into the open air, where they would have been performed in his day.
Away from the glare and clutter of the classroom, Shakespeare's words can fly among the things that inspired him - clouds, wind, leaves: "This is the air, that is the glorious sun."
Those big characters need space to rage at the sky: "Blow, winds, and crack your cheeks!" A 14-year-old Prospero proclaims his magic to the trees: "I have bedimm'd the noontide sun... to the dread rattling thunder have I given fire." If pupils see what Shakespeare saw in nature, they'll see more of what he saw in human nature. There is so much in both that has not changed, but "was ever so, since summer first was leafy".
Maybe one day we'll be able to shrink the kids and give them a boat trip round the human body. But for now, to children growing up in an over-protective and heavily mediated world, perhaps just walking alone among trees can be a fantastic voyage.