Being the last person alive is read as deep loneliness or a need for solitude. Tradition sees it as both isolation and the freedom of a world with no one watching.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.