: The title refers both to the multiple parties Steven throws and the many biological ages he experiences in a single day. Steven Universe S1E13 "So Many Birthdays" Recap - TV Tropes
: Steven learns that his physical age is tied to his state of mind. After feeling "too old" for childhood traditions, he begins to age rapidly, eventually becoming a frail old man on the brink of death. [S1E13] So Many Birthdays
: Fans often cite this as a turning point where the series transitioned from a "slice-of-life" cartoon into something with much heavier emotional stakes. : The title refers both to the multiple
: The episode establishes that while Gems do not age and are functionally immortal, they can still be hurt or killed. he begins to age rapidly