I get that that was the plot point with this movie, but come on now. He was apx 51 and she's apx 17 in 2002 while filming. It's just creepy to me even if it was just a close friendship or not. They kiss at the end, so it was more than platonic. They were in love but knew the age difference made it impossible...ooh how artsy. Build a time machine then get a room.
When seen through the lens of isolation and loneliness, the age difference absolutely makes sense. Is their relationship one as lovers? Father-daughter? Two lost souls swimming in a fish bowl, year after year? Ultimately, it doesn't matter, but if their age was much closer, and if that subsequently tempted them into bed with each other, the film would have been a complete wash-out.
Do you (the generic "you") find yourself rooting for them to kiss? and make love?
Do you find yourself hoping that they share some intimacy without sex?
That's the beauty of this movie, the isolation creates an ambiguity that works in so many ways.
- - -
...and that, my liege, is how we know the Earth to be banana shaped.
I interpret the relationships based on two bits of dialog from each character. Charlotte says she's searching for a reason to be and Bob tells his wife from the tub that he wants his life to be changed, impacted by his experiences in Japan, They offer each other what they need, regardless of age. She needs purpose and he offers her the chance to expose him to a vibrant life. She offers him a chance to learn new philosophies. He offers her a chance to see that her learning and experiences can be shared and developed upon.
She is lost, the temple and monks do not effect her soul. His excursions to the bar and pool only increase his sense of loneliness in the world. When they come together, it is like the fireworks going off as projected on the disco balloons, brief ecstasy. \ My imagined ending whisper is that he told her to call him when she returns to LA in a week so they can continue their joint study of happiness. Each as an explorer and no matter of import to their individual ages.