Threshold concepts, or gateway ideas, are ideas that, once you get them, change your way of thinking permanently. There’s no going back. And you’re stuck with it.
Realising that ‘you’re not the child your parent had in mind’ (as Peter Block says) is a big one.
Deep systems insights like power+systems dynamics or the Viable Systems Model are very much in this category.
Understanding that aggression often comes from being wounded and attempting to protect that wound.
I think that my RedQuadrant tool shed is full of these kinds of concepts, the things which shaped my thinking and which I never looked back from.
Meyer and Land, the scholars of this, say
“‘Threshold Concepts’ may be considered to be “akin to passing through a portal” or “conceptual gateway” that opens up “previously inaccessible way[s] of thinking about something”
This doesn’t mean they are Eternal Truths For The Ages — it means that they change something in you — and as Marshall McLuhan said, ‘every extension is an amputation’. Good threshold concepts empower, inspire, and transcend and include.
What springs to mind for you as the big idea which changed you permanently?
For more on the RedQuadrant tool shed and going through some boundary concepts with me and a group of peers, see
You can read more about this thresholds idea via https://stream.syscoi.com/2019/12/03/the-threshold-concept-an-introduction-and-overview-to-the-concept/
and an allied concept in learning here: https://stream.syscoi.com/2020/04/05/theory-legitimation-code-theory-and-semantic-waves/