A conversation between Alice and the Queen of Hearts:

‘The rule is, jam to-morrow and jam yesterday — but never jam to-day.’
‘It MUST come sometimes to “jam to-day,”‘ Alice objected.
‘No, it can’t,’ said the Queen. ‘It’s jam every OTHER day: to-day isn’t any OTHER day, you know.’
‘I don’t understand you,’ said Alice. ‘It’s dreadfully confusing!’
‘That’s the effect of living backwards,’ the Queen said kindly: ‘it always makes one a little giddy at first —’
‘Living backwards!’ Alice repeated in great astonishment. ‘I never heard of such a thing!’
‘— but there’s one great advantage in it, that one’s memory works both ways.’
‘I’m sure MINE only works one way,’ Alice remarked. ‘I can’t remember things before they happen.’
‘It’s a poor sort of memory that only works backwards,’ the Queen remarked.

This may be the most succinct definition of design I can understand: Our task as designers is to remember the future.