On the subject of learning Greek, it presents a particular problem for many of the Brits here. The principle one is because meny of us are retired and into old age and we just cannot memorise new information like we could when we were much younger.
Additionally quite a few of the older residents, including myself, suffer from deafness - predominantly high frequency loss - so that we cannot differentiate between the various sibillants, particularly at the beginning of a word. For instance, we cannot tell whether the word begins with, say, an "s" or a "t" or an "f". For me, this is a huge problem in English (despite wearing two hi-tech hearing aids) and this is when trying to deal with words that are familiar to me. When it comes to Greek words which I may, or may not, know, the problem results in immense frustration.

I've done the EU-funded Course 1 twice and have been having private Greek lessons once a week for the best part of two years and I'm still unable to enjoy conversational Greek and I am only too aware of my shortcomings in this respect.
From my experience I would say that most of the older foreign residents that are fluent have been over here for many years and are in many cases married to Greek nationals. Just ask yourself why pre-school children learn Greek very quickly. They are at an age when they are assimilating information as fast as it can be fed to them, their hearing is good and so is their short-term memory.
I'll keep plodding on, but I'm not too hopeful. Surrounded by friendly Greek neighbours, I'd be happy to learn (
and be able for always recall - that's the important bit!) just one new word a day, but it's a struggle!