I don't even know where to begin! lol I have been fascinated with foreign countries and people from other countries since I was still really, really young - even as a child. My first time abroad was at age 13 (although I don't really count that experience as such - long story), followed by what I consider a real experience abroad at age 14 when I came to the US for the first time (I'm Brazilian). Between ages 14 and 19 I visited several countries (mostly the US and countries in Europe), but at age 16 I was already completely open to actually living abroad. All the differences were fascinating to me - culture, language, scenery, food, customs, lifestyles, perspectives, communication, transportation, technology.. you name it, I've been fascinated by all of this all my life.
Fast forward to the present and I've been living in the US for the past 2 years and here's how I feel about the actual experience:
I'm still fascinated by all that!!

It's simply a fantastic way of experiencing life.
The downside: I knew I would miss some things, but I wasn't either consciously aware or fully prepared for the things I'd miss - and how intensely I'd miss them. I think certain aspects of living abroad catch you by surprise. In my case, it's mostly how intensely I miss my family sometimes and not being a part of my baby nephew's life. I wasn't there when he was born last year. I missed all of the milestones of his first year - and will continue to miss future ones. This is the hardest thing for me to deal with, out of everything else. Second, not being there for birthdays and special celebrations or family gatherings. I absolutely LOVE Christmas in the US, but having to wish my sister Merry Christmas over the phone hits me pretty hard.
Since I'm married to an American, there's also the whole questioning about raising a child (if I ever have one) outside of my own cultural roots. As much as I can pass along a lot of things, it just isn't the same. Still working on this one.
I miss the food!!! lol
This is an odd one: I'm starting to find it hard to be as articulate (in writing and speaking) in Portuguese as I used to be, which is completely bizarre to me!!! Of course you never forget your own native language, but your brain is on a different switch the majority of the time, so every now and then I'll find myself looking for ways to express certain things and not being able to be as articulate or find just the right words. I didn't expect that to happen at all, it's totally bizarre and I doubt it happens to most people.
That being said... despite these things, I'm having a magnificent experience and I wouldn't change a thing. This has been one of the most rewarding experiences of my life, the amount of personal growth that this type of experience allows for is unparalleled. I'm always (and still) excited about the abundant possibilities for exploring all of the aspects I mentioned in the first paragraph. I may have been born with wanderlust, I find the discoveries extremely exciting and I often feel this burst of life just by realizing how many different things I'm being exposed to.
I have also come to appreciate the positive aspects of the downsides. Being away from my family has actually brought us closer together and helped us make the best of our in person interaction opportunities. Missing the food has encouraged me to explore options, find ingredients and learn how to cook dishes I wouldn't have learned how to cook if I wasn't here, simply because there are more convenient ways to get them back home. Diving so deeply into the language has forced me to improve my communication skills in English which is also gradually helping me become a better writer - in general.
Being married to someone from another country is a separate subject altogether, but it's an intrinsic part of my experience abroad, so from that perspective alone, it magnifies the experience as a whole - I believe it would be completely different to live abroad with someone from your native country. I find it fascinating to learn about his roots, how he grew up, to have our Christmas traditions mixed in the celebration, to have both typically American and Brazilian dinners, to hear his perspectives based on his cultural roots and so on and so forth. Fascinating stuff!!!
I feel very, very alive!!

My best description is: to me it almost feels like being a child again, surrounded by things to be discovered and learned all the time. Personal development at its best.