[mmooss]

> we have no clue what we don't know

We have very good ideas about it, including the issue described in the OP. We also don't know how gravity and the other forces work together. We don't know where other life is in the universe. We don't know how to travel to other stars. We don't know what is under the surface of Europa (but we'll soon find out).

And we have a very good idea of what we know because our theories, based on our observations, predict things accurately.

The original upthread comment and followup seem like taking some philosophical questions to logical extremes.