Ex-boyfriend passed away...

The strangest thing happened this morning. First off, my ex passed away the end of April due to an illness. The last time I saw him was maybe 2 yrs ago. We stopped communicating through email for reasons that we know about. There is a song that reminds me of him when I hear it. It takes me to the exact place and space. This morning the song happen to come on out of nowhere on the radio. Coincidence? Or maybe he's reaching out?
I was so sad when I heard about him, seems so unreal.