This was deep.
Although the meaning could be subjective, I think it could be summarized into something about youth and being good for himself and for the level. The narrator has seen that Polly needed help, as she gave colours to the level, but her efficiency was drowning. So he started to help her more, until she has done what could have done.
There are multiple meanings now. For me, it was that while we're young, we need to have fun but also helping each other.
Anyway, good job for the storytelling!