I think part of it is that some items/patterns/etc might actually mean absolutely nothing. It might be a dead end even with perfect knowledge.

Some Neanderthal was fucking around with some rocks one day and we look for some meaning in the remains. Was it a tool? Religious artifact? Nope, just Bobby Neander being bored and hitting rocks together into a shape with no meaning.

To be clear, that doesn't mean it's not worth trying to find the meaning if there is one.