I think an active imagination can 'fill in the blanks' and lead to much wider fears.

I know it seems vivid because my imagination fills in all the bits another person wouldn't understand.

It provides that abrupt change we seek, and our imaginations fill in the rest.

The site is crumbling, but enough remains that the imagination can fill in the blanks.

Actually, it argues for the opposite, since imagination can fill in details that memory can't.

Either the imagination fills in the details not actually seen, or it tunes out.

Driving through a strange city at night, his imagination filled in what wasn't seen.

He wished he had been able to see her expression, but imagination could fill in a great many gaps.

Your imagination fills in the blanks with exactly what you want.

Their own imaginations would fill in the gaps.