You expect proof, or a literal pathway of thought and explanation, because it has served you well. This is the guaranteed route to proving an idea, if such a literal route exists. Such ideas are grounded in axioms that exist or can be built on smaller already established truths.
It is far more difficult to explain literally a strong hunch, that an excellent intuitive thinker has but which is lacking the necessary foundation axioms. Maybe this hunch or novel idea cannot be structured upon existing truths, because it looks beyond its current viewpoint. Or maybe the idea is about a situation that is happening outside the established system.
This doesn’t make this idea less valuable to pursue further. It might just be several magnitudes harder to wrap ones head around.