Some things are private. I mean, we're grown-ups now. You don't share everything.
The quote suggests the importance of privacy and boundaries in adult relationships. As people mature, they learn that not every detail of their lives needs to be shared openly with others. This awareness leads to a more selective approach to personal information, recognizing that some things are meant to be kept private.
In the context of the book "Shopaholic to the Rescue" by Sophie Kinsella, this idea reflects the characters' development...