The Link between Septimus and Clarissa

Note: I will not be putting any GIFs on this post because I felt like it took away from the words I was trying to say instead of adding to it. Sorry for the comparatively dull looking post. I felt it was most appropriate.
Mrs. Dalloway is about way more than Mrs. Dalloway. The novel is also focused on Septimus Smith, who is never connected with Clarissa personally but has interactions with everyone else in Clarissa's life.
Both Mrs. Dalloway and Septimus Smith are intense and sensitive. Clarissa's composure is veneered in a lie of vapidness. She wants to keep her most serious musings to herself; according to her, no one else would understand them. She is wife, mother, and hostess, but she is never completely relaxed and open with anyone. No one is allowed to see the depths of Mrs. Dalloway's soul. And when Clarissa uses dark to describe her soul, she does not mean dark to connote something necessarily evil. Clarissa finds her soul to be a place of retreat. Perhaps this is not the healthiest attitude to take towards oneself, but Mrs. Dalloway is considered sane.
Septimus Smith is deemed insane. He has almost wholly retreated into his private world. Notice, for example, how his reaction to the noise of a car backfiring echoes and amplifies, but differs from Clarissa's reaction. Clarissa immediately thinks that she has heard a gun shot. World War 1 is just over. An era of terrifying death and violence has officially ended. Yet the fearful sounds of war remain. England is still in fear for what just ended.
Even though Septimus is a WW1 veteran that is struggling with "shell-shock," he does not hear gun shots when the car backfires. Instead, the noise is the sound of a whip cracking ("The world has raised its whip; where will it descend?"). Everyone else is startled, but Septimus is terrified. We have officially seen two confused and frightened people within the crowd of London.
Two different perspectives of the same moment were shown from two different people that live very different lives. Which one is the most real? The truth is that neither of them are more or less real then the other. Clarissa will learn this through the suicide of Septimus, but will never have any ability to change that reality.