They both like Ben

They both have fathers that have left them

Sal and Phoebe have wild imaginations that grow stronger when they're together. 

Their lives reflect each other's and their paths are intertwined. 

Her wild red hair

Her cobra cane 

Her skinny legs and old, falling apart slippers

Her ability to "see" things without seeing them. 

You can't stop the birds of sadness from flying over your head, but you can prevent them from nesting in your hair

Everyone has his own agenda

The journey of a thousand miles begins with a first step.

In the course of a lifetime what does it matter? 

She loses her job

She loses her baby

She falls in love with someone else

She doesn't love her husband anymore

She suffers from migraines

She feels like she lives a meaningless life

Allergies

She's struggling with her career