And the puzzle falls into place

There is a special joy in discovering the origin of a tune that has been ringing in your ears.. and when you've been unable to place the tune. The orphaned tune floats in your mind, frustrating your best efforts at trying to place it…. until one day you catch the tune in a song when you’re walking by! And then the tune has its happy reunion with the song… and the world is at peace again!

Or in a phrase that you read, which keeps popping up in your mind again and again. And the way it comes back to you with the suddenness of lightning, like a particularly difficult part of a jigsaw puzzle that falls into place finally.

Or the way something that's bamboozled you completely comes to you in a flash of insight.

The mind is a vast storehouse of forgotten thoughts, thoughts waiting to be reclaimed and relished. Maybe the joy of rediscovery is worth all the frustration that precedes the retrieval of the elusive thought.. or phrase... or song.