Hola chica!
I grew up in Spain and my parents took me back to the UK aged 15 and I always wanted to return. I used to go out every year to see my school friends and pined desperately for what I had left behind. I hated the UK from the moment I arrived.. everyone seemed so cold in comparison to people in Spain, and that´s just one difference (let alone the weather!)
For many, and complicated reasons, I didn´t return to Spain until 3 years ago with my DP and DD. It hasn´t been an easy ride.. it seems like most of the Brits out here (who have businesses) are crooks. DP has been diddled continually by them re payment for jobs done and, as you probably know, Spanish wages are sooo low! So things have been difficult money-wise. DP has never really settled, probably mainly due to the fact that he has found it slow going learning Spanish.
DD speaks Spanish fine now but misses things from the UK (she was 13 when I brought her over so I left it a bit late).
I was obviously fluent from childhood as we came out when I was only 7 and went to a Spanish school from day 1 so no probs for me in that respect but it is not as great as I remembered it as a child.
Perhaps we should have tried a different are, like Andalucia. We are in a small village in the Valencia region and find the locals to be very ignorant, uncultured and bad mannered. Not to mention abysmal drivers! They have this closed in mentality and separate themselves from the rest of Spain as if they were a separate country (a bit like the Catalanes).
To be honest I also have itchy feet and would like to try somewhere different now. I think it´s a big world to be born and die all in one place and not try out different experiences. Personally I wouldn´t mind even Greece or Italy as I learn languages relatively easily but for the sake of DP and DD I think it fair to try an English-speaking country.
We have been toying with NZ (or rather I have!!!) but would also consider some parts of the USA or maybe Canada. I don´t know. I´m reading lots of threads from people who have emigrated to these places. The main drawback with NZ is that it seems the wages are low like here so that wouldn´t be such an adjustment for us like it has been for people going there straight from the UK and English wages.
Obviously the main concern with any move is the cost of taking everything with you again, having dragged it all out to Spain with us in the first place!
Would be interested in hearing your thoughts on the subject and to know where you are in Spain.