Why must they be communicated? Surely it is the rest of civilization that decides which ideas it is ready for, and which it isn't. Go ahead and write a song like "Imagine", or give a speech like "I Have a Dream", and you'll see how well the rest of civilization responds. Civilization isn't pretty; communicating ideas the people aren't ready for gets you killed.
Knowledge that's not propogated and retained isn't cultural knowledge, it's personal knowlege. It dies with the individual.
That's one of the distinguishing elements of humans: we learn, and retain, knowledge, and transmit it beyond the individual.
We have an entire class of indivduals whose sole productive contribution is dedicated to the task of training and instructing others. No other species has anything remotely that.
Biology is an information transfer system: molecules, DNA, learned behaviour, taught behaviour. Humans came up with writing, teaching, and now electronic information, genetic engineering, and perhaps AI, as extensions of that.
Each allows for the acquisition, storage, transmission, and application of knowledge in new ways.
(I'm not saying "without limit" or "forever accelerating". But I am noting that we've far exceeded any other life forms of which we're aware in this degree.)