My advice: if you go on a mission trip, two weeks is a good max. Just long enough to enjoy the fun of a foreign country and be able to see the impact you're making for Christ. Much longer and you start to get into a routine and see the ugly side of missions work. My first week in Mexico, I knew it was all fun and games: going out to eat often, touring the big city nearby, etc. I was scared of what the normal routine was, because I knew I'd get to see some uglier stuff. The third week I was there, I said to myself: "If I went home now, I would have all these nice memories, but if I stay longer, who knows what'll happen."
Yes, I did see the other side of mission work--the Devil does all he can to stop the Love of Christ from being shared throughout the world. But the longer I was there, the deeper relationships I grew with the kids and staff. The more I got into the somewhat boring routine, the more I appreciated how God was using the people down there. I was planning on being there for ten weeks, but ended up coming home after six--and my last week was swiss-cheesed by emergency room visits.
If you want to pick up an expensive hobby, I recommend Diabetes. Blood sugar tester, test strips, lancets, insulin, needles, and an emergency supply of sugar. Take the number of doctor visits you currently have, and multiply it by five. Take the number of times per day you give yourself shots and multiply that as well. Now, take the total amount of time you spend preparing food, and multiply that by 10. And even though putting coins in the parking meter only takes ten seconds, you spend the next three hours worrying about when your time runs out.
Now, if you're looking for a cheaper hobby, I recently officially picked up laughter as a hobby. I have always enjoyed laughing, even though I don't like the sound of my own laughter. I figure: when life throws stuff like Diabetes at you, you can either laugh or cry, and laughing hurts less. Now, this is a tricky one, since there are times that crying is a good thing and laughter is just one way I ignore the pain. It's healthy to acknowledge how broken my life is, and mourn that.
I did truly have a wonderful time in Mexico, but it's hard to explain more than that. It was hot and dry. I worked hard. Yes, I learned some Spanish and got really good at converting dollars to pesos. I ate amazing food like fresh tortillas and frijoles and fruit. Yes, I wish I could have stayed much longer. I'm gonna go back someday.