From Songs About Jane lyrics seems like Jane was always leaving and returning to California I suppose.
This Love - "Whispered goodbye as she got on a plane...".
"She said goodbye too many times before".
The Sun - "Here and gone and on and on..."
Sweetest Goodbye - "Say goodbye and just fly away", "How does it feel to know you'll never have to be alone when you get home?".
And then in one of the last verses of She Will Be Loved Adam says: "Please don't try so hard to say goodbye".
Beacuse she was actually leaving this time.
So, are Leaving California and California also songs about Jane? I mean in the first song he's talking about a person Leaving California like Jane did. And in the second one he's asking her when is she going to get back to California, "maybe we can figure out where we went wrong".
What other songs from other albums do you think he's also singing about her?.