Well, as with any generalization, it's more optimized for sounding good than precision. Conveying the spirit of the principle, rather than a specific procedure or list of rules to follow. What does Anakin think the spirit means?

Hmmm... That you should be nice and honest? Because being nice makes people feel better, and you shouldn't say mean things even if they're true if they won't do any good? So - that you should say things that make stuff better?

That sounds like a good reading to Elesse. So what sorts of things can you say to make stuff better? Maybe if they examine some broad categories they can figure out where the saying came from.

Compliments usually make people feel good; those are kind and compliments should be true as well, but it's not always strictly necessary to say 'your hair looks really pretty today' or something similar. Or telling someone they need to stop being a bully; that's necessary because people shouldn't be bullied and let's assume it's true in whatever imaginary circumstance. But it's not necessarily kind- someone realizing they're a bully might make them feel bad about themself. Or telling someone a joke after they've had a rough day. It's necessary because them being sad is an overall worse state for the world to be in, and it's kind because you're cheering them up.

What if you have to lie to get the bully to stop, though?

Then you've run into one of those edge cases that're beyond the scope of the generalization. What would the spirit of the principle that Anakin deduced say you should do?

Hmmm... Try to get to a kind ending? 

Mhm. But you'd have to think carefully about how to go about it. There's not a quick and easy answer, so you can see why the generalization doesn't and in fact can't apply.

What generalizations like 'necessary, true, kind' are good for is giving you an acceptable shorthand, something quick you can check if you don't want to or aren't able to think deeply about everything all the time. In most cases, it'll work fine and you'll get an acceptable result. But sometimes you will run into things that don't fit and you will have to think deeply in order to arrive at a correct answer. The trick is in recognizing those situations when they come up and having a good enough understanding of the reasons behind the generalization that you know what correct looks like.

To take a less ethically-fraught example, say you're a professional gardener and you're designing a flowerbed for someone. You know that two species of flower don't get along and so you should never put them within two meters of each other. However, the plot that you're working on is only one meter by one meter, and the customer definitely wants both species. If all you knew is that 'these two flowers don't go together', you'd be stuck. But since you've studied hard and learned your trade, you know that the reason you don't put these two flowers next to each other is that they're competing for the same nutrient in the soil. If you add this third species, it'll replenish the soil enough that both flowers can live happily next to each other. It takes you more time and you have to add more trellises for the third flower to grow over (such that for most designs with sufficient space it's easier to just not), but at the end, you've found a way to make both flowers survive even though usually you don't even try to.

Can people be like flowers?

It's... possible, yes.

Hum...

"You and mama are pretty different."

"The flowers in that story were not stand-ins for your mama and I."

"But there's an underlying principle."

(Elesse has taught Anakin a new concept and will probably eventually stop having cause to regret that.)

Pat pat.

"You've just got romance on the brain, Anakin."

"Getting along when you're different isn't just romance," she huffs, clearly annoyed. (And, possibly, a bit hurt. Her moods have been odd and hard to read sometimes though, at least recently.)

"Your mama and I get along fine."

"How?"

"Do you want to know how we achieve getting along or examples of us doing so?"

...Hm.

"Both?"

"We communicate consistently, and talk about interests we share in common, like the Force or you."

"What about when you disagree?"

"We lay out our reasoning so the other can follow, and asses our own principles to see where they disagree. Sometimes one of us has made a mistake and changes her mind, other times we have to make a compromise."

Hm. "That sounds easy, but it's hard."

"It is. We both have to work at it."

"Can I help?"

"You already do, Anakin. You give us both a reason to work hard and do our best."