How can Hyde access memories of the original Jekyll in the TV series Jekyll?

This question is regarding the TV series Jekyll.

Hyde starts to remember memories of Tom. He even ends up recollecting memories of the original Jekyll. Since Hyde shares his mind with Tom, shouldn't the memories that he can access be restricted to only Tom's?

In case we go with the Genetic Memory theory, where the memories of your predecessors is passed down genetically, would this mean that Hyde should be able to access memories of his mother too? Ms. Utterson (Sophia) is the mother and Hyde should be able to see in to her memories as well. Once Hyde and Tom establish their mind-meld, the memories are shared. Why does it still remain a shocking surprise to Tom when Ms. Utterson confronts him as his mother? Shouldn't he have expected / known this?