Concrete, concrete, concrete
As Chip and Dan Heath captured so elegantly in Made to Stick, to get your point (your story!) across you need to be concrete, always. Concreteness is one of the six elements of their SUCCESS rubric for telling “sticky” stories.
More specifically, you need to use language that speaks to the shared vocabulary of the two people who are speaking. If you have more expertise on a topic than the person to whom you’re speaking, this will feel like dumbing down your language. It’s not. It’s making sure there’s no possibility for confusion where there doesn’t need to be.
Think about it: every time we use language that is not in people’s day to day vernacular (I mean that literally: language that they use every day; concepts that are so familiar that they don’t require a second of extra thought), we are asking them to spend mental effort deciphering language rather than resonating with our story. That is wasted attention and the fault is with us for asking them to expend it.
This is not (not not not!) a question of their intelligence, this is a question of your shared vocabulary and where you want them to use up their precious, finite attention.
This means that every time you’re speaking, you’re saying “for example,” a lot.
It means, for example, that you’re not saying “ethical sourcing” when you could be saying “six year olds in factories.” You’re not saying “assess baseline data” when you could be saying “go to 10 customers’ homes and record whether or not they have corrugated tin roofs.” You’re not speaking about millions of dollars when they live and breathe crores. You’re probably never, ever talking about “paradigms.”
Instead, you are trading conceptual terms for concrete ones, exchanging categories of things (“processed cotton”) with specific and familiar examples (“thread”). You are starting with one specific, familiar item (or action) and generalizing from there, rather than staying at the conceptual level and assuming they’re smart enough to boil it down to the specific. They are, but they shouldn’t have to.
And you’re doing this in a disciplined way, time and time again, because that’s what it takes to have this become natural to you.
Live in their world, speak with their language using vocabulary that parallels their reality, not yours, and they’ll finally start hearing you.