what does jekyll see as the value of seperate identities?

In his final parting note, Jekyll reveals that he often felt like a "charlatan". Jekyll says he spent his days as a sociable upstanding citizen while repressing the darkness that lies inside. As Mr. Hyde he felt alive and full of energy. He also did not care about other's perception of him. This, for Dr. Jekyll felt liberating. This is really a commentary on Victorian social mores. The repression of anything deemed "undesirable" in behaviour yearning to break through.