Languages learning curve can be very funny. Phonetic regularity plays a lot in this game, for instance. French and Italian are very similar languages (more than Italian and Spanish), yet they are so phonetically apart (with Italian at the extremes of regularity and French at the extremes of complexity) that it's complicated for Italians to learn French in the first steps: then the curve flattens a lot.
Italian itself is a strange beast. It is, perhaps, the most single latin language to learn for a random speaker of some other language, at least at a level where you can talk and understand decently, but it is almost impossible to master, even for Italians.
> but it is almost impossible to master, even for Italians.
Well depending on your definition of mastery, that's probably true for nearly every Western European national language since they all have some degree of artificiality and prescriptiveness. Officially, everyone from Lombardy to Calabria speaks "Italian" but what is actually spoken in each region will differ heavily from the national standard.
Thanks for creating Redis, by the way.