Ok.

The is and the what was.  How they mingle and collide.

The past can be a gruesome stalker, cruel and unrelenting in its interferences, making even happy memories bring only pain.  What once seemed lovely becomes a mockery, and this current state of unhappiness is the punchline.

"Was it all in my head?"
"Yes, of course it was and it is and it will be."

Memories can also be a soft light amidst darkness; a gentle reminder of peacefulness and good things. Here the past becomes a saintly mentor, holding your hand, bringing you warmth and comfort.  What once was lovely becomes even lovelier in the haze of remembrance.

"I hold all that in my small head?"
"You don't hold it. You are it."

Being a child of the modern world is a difficult thing: Belief does not seem to be an option and Truth is what you make of it.