I’m assuming you’re thinking about:
How Can I Describe Something They’ll Understand In The Future But Don’t Today That’s As Revolutionary As the modern understanding of the Renormalization group [and its central place, long beyond being a mere trick for handling infinities]
I’d suggest figuring out what is central and core to whatever you want to explain that’s futuristic.
So for the case of the Renormalization group, you’d have to really emphasize the central importance of Scales.
And you’d need to not just get a nodding head agreement but persist until it ‘clicks’ just how crucial scales are.
So whatever the equivalent to scales is in whatever futuristic idea you have, would likely be the thing you’d need to emphasize in your education of the present people.