Although I would define myself as an ENFP (Extroverted, iNtuitive, Feeling, Perceiving) and most people know me as one, I'm actually a "closet introvert". Until 8th grade, I was very quiet and shy. Then one day (quite literally) I decided that I was missing out on a lot of fun by being shy and that from now on I was going to be outgoing.
After that, throughout high school and college, I was much more sociable and talkative and took on several leadership roles.
Since coming to Thailand though, I've gone back inside myself quite a bit. I've become much quieter - observing and listening, and spending a lot of time alone. I often don't even feel like communicating with friends and family at home (no offense).
Despite my best efforts to be fully accepting of who I am, I still find this quietness/introversion a bit distasteful - a leftover from my adolescent rejection of this part of my personality.
I think my emotional "shell --> core" reaction is caused partly by the differences of living in Asia (as westernized as Chiang Mai is), and the shock of being so far from loved ones. But partly, I'm realizing that life goes in cycles. You can't be "on" all the time or you'll burn out.
Sometimes you work hard, and sometimes you relax, sometimes you go out and explore the world, sometimes you curl up at home with a book and cup of hot tea. Sometimes you're on top of everything and other times things pile up unorganized... happiness and sadness, energy and lethargy all have their time. I'm working on being okay with this.
The earth goes in cycles we call seasons, and sometimes it doesn't make sense to me that we don't follow the earth's lead. There's a time for planting, growth, harvest, and rest. That makes so much sense, yet the way we structure our lives (particularly with respect to work) asks us to be harvesting output all the time, giving the same amount of energy year round with no time for the soil/soul to rest. I may be quiet and reclusive right now, but it's okay, it's not permanent; I'm just giving myself a long-overdue winter.