Fancying a cart before it is built

The man who is rich in fancy thinks his wagon as good as built already. Hesiod. Works and Days. Line 456.

Roman stone relief depicting a "soul " on the journey to the afterlife, coached by the hooded mythological Celtic figure Genius Cucullatus, found bricked into the cathedral of Maria Saal in Carinthia, Austria.
Image courtesy of Wikimedia Commons user Binter.