
There's the rub!

Qui casca l'asino!

Qui casca l'asino!
Meanings
Exclamation indicating a difficulty, trouble spot, obstacle, and the like, that could be very difficult, if not impossible, to deal with
Examples
Tourism is a great source of profit for Italy's art cities, but with overtourism quality yields to quantity – and there's the rub!
Il turismo è una grande fonte di profitto per le città d'arte italiane,
ma con troppi turisti la qualità cede alla quantità – e questo è il
guaio!
Your project is interesting, innovative and promising, but – and there's the rub! – you can't seem to find funds for its production
Il tuo progetto è interessante, innovativo e promettente, ma – e qui
casca l'asino! – non riesci a trovare un finanziatore per la produzioneOrigin
William Shakespeare uses this line in his famous soliloquy "To be or not to be" in Hamlet (Act III, scene I):
… To die, to sleep;
To sleep: perchance to dream: ay, there's the rub;
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil,
Must give us pause.
In this case, rub symbolizes an impediment to Hamlet's suicide.
This term was initially used a few years before Shakespeare's time and, according to most sources, it all began in the ancient game of bowls - known as lawn bowling by Americans and Bocce by Italians. A rub, in fact, is a flaw in the playing surface that alters the trajectory of the ball.
… To die, to sleep;
To sleep: perchance to dream: ay, there's the rub;
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil,
Must give us pause.
In this case, rub symbolizes an impediment to Hamlet's suicide.
This term was initially used a few years before Shakespeare's time and, according to most sources, it all began in the ancient game of bowls - known as lawn bowling by Americans and Bocce by Italians. A rub, in fact, is a flaw in the playing surface that alters the trajectory of the ball.