Look who's out of rehab finally! She's doing well thank you for all the get well wishes! #myneighbornorma

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When Chris Salvatore moved in across the hall from Norma Cook four years ago in a Los Angeles-area apartment complex, the 31-year-old actor waved to his 85-year-old neighbor for a few weeks before finally knocking on her door and introducing himself.

"The day I entered her apartment and spoke with her face to face was the day my life was changed forever," Salvatore says.

He learned that Cook had no family living in California and that she suffered from a long list of illnesses, including leukemia. The pair quickly became close friends, as Salvatore took her to doctor's appointments, cooked with her and they ran errands together. He shared their adventures on social media with the hashtag #myneighbornorma.

But recently, Cook's health deteriorated and she was in and out of the hospital and rehab several times. She once spent weeks in the hospital fighting pneumonia and breathing issues. Eventually Cook was told by one of her doctors that she could no longer live at home unless she had 24-hour care. Because Cook had no money saved to pay her health care costs, Salvatore started a GoFundMe account to help cover her bills.

But caretakers are expensive and Cook quickly went through the $50,000 they raised. Knowing her days at home were limited, Salvatore invited Cook to move in with him to save money.

"She loves it! I do most of my work at home so I am here most of the time to care for her so it only made sense to the both of us," Salvatore wrote on GoFundMe. "She is my adopted grandmother after all and I am her grandson she never had."

Somebody's thriving 🥂 #myneighbornorma

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Cook still has weekly hospice health care visits and regular visits from caregivers, so any funds raised cover those expenses, he wrote.

Though doctors say Cook's days are very limited, the pair are enjoying spending time together drinking Champagne (her favorite drink) and snuggling with her cat, Hermes, who also made the move.

Cook has lived in the apartment complex for about 30 years and doesn't want to leave.

"She does not want to budge," Salvatore told "Today." "My apartment was the only place she would have moved. She has strong opinions about where she wants to carry out the rest of her days, and she wants to stay here."

Salvatore says he feels like the relationship was fate.

"Moving her in... it feels as though it was meant to be all along," he said. "It's really fulfilling to be there for her."

Happy New Year from Norma and me. She rang in 2017 in style last night! 👵🏻 #myneighbornorma

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Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.