I have just stumbled across this beautiful thread and realised that I have one without having realised it.

I have a rear vision mirror that pops up when I feel down. A rear vision mirror that shows me the dark places I've been and that those places are so far behind me and I know I won't be going there again.

There is the box with all the theatre and concert tickets. A box full of memories of pure enjoyment and I can revel in the memory.

Then there is the box with all the tickets still to come; performances to look forward to.

Right on top of the box is a reminder to sing ... and I do ... I sing all the depression out of my system.