Meaning of "there life turned on me"?

Hello everyone. I am reading a novel, and I came across this expression. Could you please let me know its meaning?

“Clara Brunschvicg, I could do this for the rest of my life—me and you, alone together, whenever, wherever, forever. Spend every minute the way we’ve done today, winter, car, ice, stones, soup, because one hundred years from now, those minutes are all we’ll have to show for ourselves, all we’re ever going to want to pass on to others, and frankly, in one hundred years they’ll all forget or won’t care or know how to remember, and I don’t want to end up like my father with dreams of love and of a better life he’d been robbed of or is still sailing out to. I don’t want to pass by your building in thirty years and, looking up, say to myself or to the person I’ll be with that day, You see this building? There my life stopped. Or there my life split. Or there life turned on me, so that the person looking at the building right now and talking to you is, ever since that one winter so many years ago, still on hold; the hand holding your hand is a phantom limb, and the rest of me is prosthetic, too, and I’m a shadow and she’s a shadow, and, as in Verlaine’s poem, we’ll still speak shadow words of our shadow love while the decades trawl past us as we stay put and hold our breath."

- André Aciman, Eight White Nights, Third Night

This is a novel published in the United States of America in 2010. This novel is narrated by the nameless male protagonist who meets Clara at a Christmas party in Manhattan. Now the protagonist is thinking the words he wants to tell Clara in his mind.

In this part, I wonder what the underlined expression means.

I learned in the dictionary that "turn on" can mean "to suddenly attack", but I am not sure how that meaning (if I found a correct definition) can fit into this context. o_O

Thank you very much for your help.