Why are my children blind to dirty pots?

[colditz]

They will quite willingly load the dishwasher, they are young enough for this to be a novelty chore, but they've just come and told me they're finished.

The surface is covered in dirty pots. The children are six and nine. Why can't they see them? The dishwasher is nearly empty, and the surface is covered.

What is going on?

Just mine then?

I sent them back to redo it, with the instructions that if it doesn't go in the bin or the cupboard, it goes in the dishwasher.

They've mainly done it now ...

My eldest loads the dishwasher every night as part of his chores to earn his allowance. He regularly misses things and he's 18!