Valid, non-trivial theories that seem to depend on highly-technical arguments can be expressed in simpler, broader strokes from within the proper framework.

This is a hypothesis instead of a theory, because I can’t offer any kind of proof, only examples.

Ex. 1: The Monty Hall Paradox (Perhaps some people think the argument for this is not very technical – I would argue that this is because the framework for proper understanding has become popularized in the course of explaining the initial paradox.)

Ex. 2: Non-Euclidian Geometry Along with modern relativistic physics, these provide a relatively accessible theory for explaining real-world phenomena that are not cleanly understandable in previous paradigms.

Ex. 3: (This is a good one) Kepler/Galileo/Newton’s model of planetary motion versus Epicycles

The above examples are all mathematical or scientific, because those are easily documented and explained, but the principle applies to less exact sciences as well. Consider technology from the vantage of a pre-industrial tribesman. Explaining how even a lightbulb works would take the most complicated explanation until he had the vocabulary to understand electricity.

Corollary: Theses which have been declared valid but rely on very complicated and technical explanations are likely gateways to new fields of understanding.