Pink, I had something similar happen about a month or so ago. I was in a difficult crying spell and a song came on the radio 'bright sun-shiney day'.

I think I mentioned this before, the automatic image of T and I laughing and walking along a boardwalk in Jersey.

Then once or twice after, when I was more depressed than usual, this same song would be on the radio...odd

It does feel so real when the image is there and it is NOT day dreaming. I could almost feel the hot sun on the boardwalk like years back.