question for the actors

My compliments to all the actors.
Today in Rome I have seen the musical of the dr Jekyll and mr Hyde and after the end during the questions I would have liked to ask:
how long have you spent for learning to memory the whole script? I ask it because to me it is seemed very long and complex.
thanks
bye bye
PS: YOU ARE GREAT!!
(sorry for the possible errors but I come from Italy in the same city of Ale 91TR)