Wikipedia
Honza is a Czech fairy tale hero, sometimes called Hloupý Honza (Dull Honza), Líný Honza (Lazy Honza) or Chudý Honza (Poor Honza).
Honza may also be grammatically correctly translated as Jack. In Czech language, Honza is traditionally used as the diminutive form of the name Jan (Jan → Honza → Honzík → Honzíček).
In original uses, Líný Honza is the lazy and inept son of village farmers. His parents send him "to the world" to take care of himself and get experience. On his way, he meets seemingly impossible obstacles (often involving dragon) but outsmarts them all and returns home with fame, riches and a princess as his wife.
While sometimes called Hloupý Honza (Dull Honza), he is not really dull and in more modern fairy tales he often loses other negative characteristics too.
Such figures became national personification – often suggested as mirroring the national character of Czechs (the nation had unexpectedly risen up, from low classes, struggling to establish itself as an independent entity). Comparison of "dull" Honza with lot of " common sense" (as opposed to knowledge obtained by studying) with aristocracy portrayed by princes which are unable to overcome obstacles Honza did overcome might also refer to fact that for big part of history (most of) Czech aristocracy was separated from people and often not really Czech (but German and Austrian).