We know a great deal about 5% of the luminous and positive mass universe. We know one or two things about dark matter and dark energy.
We know a great deal about biology.

The distribution and growth pattern of the known universe roughly resembles that of slime mold and vice versa.

We don't know the definite age of the universe or if the Big Bang was an initial collapse event or an expansion. It could be younger than 14 billion or 28 billion, but the data does not agree between distant observations and nearer nova measuring stars.

My personal opinion is that the inflation theory is nonsense and that dark matter is the unique residue of the matter-antimatter annihilation.

In some ways, our fundamental understanding is still similar to ancient Bhuddist writings.