Teaching is, and often should be, a stealth activity. Let me take a charming example: my kids learning to cook.
Cooking is one of the most important skills a human being should have. If you can cook, you can exert some control over your diet. Your diet represents probably 40% of your long-term physical health (with exercise and sleep being the other 60%). If you can’t cook, you are at the mercy of family, friends, restaurants and corporations for what you can eat. The first two in that list probably have your best interests at heart. The other two? Not so much. So it’s essential parenting to make sure your kids can cook.
The key ingredients in cookery are:
1) Recipes. You can use other people’s or invent your own, but you do need some kind of blueprint.
2) Ingredients. You must be able to find and select the ingredients that are right for your recipe.
3) Cooking techniques: chopping, boiling, frying, baking etc.
To this end, we let our kids watch shows like Great British Bake Off, YouTube channels like Tania Burr, Nerdy Nummies and so on, because children copy what they see, and while this does tend to encourage some odd habits and turns of phrase (some baking is always done in an American accent in our house), it also leads to exchanges like this:
“Daddy, I want to make a [insert name of vile sugary thing here]”
“Ok, make a shopping list”.
The child then gets a piece of paper, and writes out the ingredients (see how we sneak in some writing practice there?), and we go to the shops. In the shop, we find the ingredients. The kids have to read the labels, and make sure they have enough of everything (for which they need arithmetic). We then buy it, go home, and get to work. Of course, boring old daddy doesn’t like watching the video in the kitchen; oh no, the instructions need writing out too! (“I don’t want flour on my mobile phone…”)
And then we follow the instructions, make the triple-caramel-quad-choc-sprinkle-covered diabetic extravaganza, and eat it, to all-round delight.
The point is, by letting them follow their own interests, we create a momentum in the direction of ‘command of diet’. Now all we have to do is to gently steer that momentum in a healthier direction: “we can only eat that after dinner. So what shall we have for dinner?”; “kids who come shopping get to choose what we eat”; that sort of thing.
All of this is why my elder daughter can bake pizza from scratch, makes a mean chicken pie, and has very strong opinions about “store-bought” pastry. My younger daughter is less interested, and so less skilled, but it’s still perfectly normal for her to choose something she wants to make, and set about establishing the recipe, choosing the ingredients, and making it, commandeering whatever help she needs in the process.

Grace baked this Pavlova ‘just because'. We helped put it in and out of the oven, but otherwise were not needed…

The major downside is we eat far more crap than we otherwise would- it plays hell with my low-fast-carb diet. But it’s worth it in the long run because whatever diet my kids choose to follow as adults, they will be able to make from scratch, and control exactly what goes into it. I hope they’ll choose wisely, but whether they do or not, at least they will have the choice.
I take the same attitude towards teaching swordsmanship. It’s not for me to sneer at a student who secretly wants to be an elf, or even an ewok. Whatever brings them to the sword is inherently good. It’s then up to me to gently steer that momentum in a more rewarding direction. This is why I’m not upset in the least by the tournament scene, and why I begin all my classes by asking the students what they want. Sure, sometimes they ask for things that are bad for them, so I redirect things a little but make it clear that it’s the closest I can get them to the goal they set. It would be fundamentally counter-productive to shut them down or bring their enthusiasm to a sudden stop.
This reminds me of steering a boat (as I did on my trip to Guernsey in September). When the boat was stationary (also known as ‘dead in the water’), I couldn’t steer it at all; but when it was under way it took only the gentlest touch to guide it right or left. Sometimes, a wave would hit and bash the ship off-course. Then I let it go, and when the crisis passed a moment later, another gentle touch brought it back to the mark.

I've been thinking a lot about teaching over the last dozen years or so, and have put together an online course to help historical martial arts instructors teach better. You can find it here: https://swordschool.teachable.com/p/how-to-teach-historical-martial-arts-or-anything-else