The "to do" lists.

"Flexibility" is a lifestyle that you must embrace as a missionary if you are going to keep your sanity. For instance, Tim and I had a schedule that we had set for ourselves for this past Saturday; we were going to get up early and get many things accomplished.
The first thing was that we overslept and while we were still getting ready for our day and before we had even had breakfast we had a visiting pastor at our door. He stayed two hours and five minutes after he left we had two other pastors arrive; they also stayed two hours. By the time they had left it was after 1:00 and we had not accomplished anything on our "to do" list for Saturday. In addition, a single missionary lady needed our assistance for a little project that we were more than happy to help with.
Sometimes you plan to bake and the power goes off, or you plan to go to town and take care of some business and the places you go have decided to close early for some unknown reason. We have guests drop in or we spend long hours at the Bible College because there are multiple problems/situtations that develop that need your attention. Or, maybe the dog gets away and you have to go looking for her. The pipes break or the workers have a problem that you have to help them with... the list goes on and on of the endless possibilites that drive home the need to be flexible and at the same time help you work on that all important virtue, "patience".
You must adopt the African philosophy that people are more important than schedules and there is always tomorrow.
"Haraka, haraka, haina barika"; an African proverb that means that there is no blessing in rushing. So, we take a deep breath, take things as they come, smile, serve some hot chai (tea) to our guests and enjoy life as it comes along. The other option is to get frustrated, miss opportunities that come with every "interruption" for fellowship and relationship building, and develop stress related illness.
It also helps to make your "to do" lists in pencil instead of ink.
Be blessed.