Over the course of the episode, the narrative keeps changing from Syd's desire to connect with others to being bullied and self-harming until you realize the common thread that connects all of these events, namely the human strive of survival. Adversity is what makes us stronger. I bet it sounds clichéd to a lot of people who think have had a tough life (I can hear them mumbling: "what doesn't kill you makes you stronger) but for those of us who truly suffered like David and Syd, this episode is a revelation that had a great impact on me (a positive one). Possibly a greater impact than countless self-help books that I've read or therapy sessions that I've attended and for that, I think this episode has been the best one yet thus far, thank you!