death is a complicated thing. i dont think any of us fully understand it until we are gone. im personally atheist but i like to think about my lost loved ones looking down on me from the heavens. but as far as that feeling you experienced i had the same thing once. my mothers side lives in a slavic country and i often spend summers there. when i had left after my month to go back home to america i was sure i had said goodbye to everyone, but i guess i hadnt said goodbye to my great grandmother and great aunt. i knew it was a mistake and i had an immense fear i would never get to see them again and i had forgotten to say goodbye. fast forward 3 months or so my great aunt passed away. i had a similar feeling to what you may have described but i brushed it off as nothing because how would i know my great aunt would die. touching back on me being atheist, even though i do not believe in god i do believe there is a spiritual side to life. i believe many interpret that as god, but i see it just as an equal flip side of science or fact. so maybe that is why. but i suppose we will never really know. all we can do is ramble on.