In the Backseat

to me, the "backseat" is a metaphor for living a life that you are no longer in control of emotionally.

the imagery of a family tree "losing its leaves" and the line "alice died," seemed to suggest that a family member of hers has died ( i imagine a younger sister or something). after this, the speaker in the song simply can't function and spends her life in the "backseat," letting other people make decisions for her because she simply doesnt care anymore. the fact that the speaker watches dreamily from a window while other people are "driving" her, and also the word "asleep" imply more passivity.

as for "i've been learning to drive my whole life," maybe this traumatic event (a sibling or other family member dying) happened when she was very young and she never recovered from it. she's been gradually learning how to cope but she still isn't ready to take the wheel.

i could be completely wrong about the details, but nevertheless this is a beautiful song.