Crackpots.

With a bit of prompting from a friend, I think I've worked out the significance of the potsherds. To cut a long story short, I belive they relate to an incident in my past, and represent the destruction/twarting of hard work by (buried) fear and humiliation. From this I can extrapolate that this is something I need to fix properly both for my own good and for those around me (rather than something I've brought upon myself and therefore ought to just suck up and deal with).

So. Brain donors. Form an orderly queue...