A reminder is a solution. These questions are actually solutions because they prime people. These kinds of questions make people realize that they have problems and they also implicitly provide a solution. For example, if I ask if you took your pill and they you realize you did not, then you will remember to take your pill and your problem is solved. Most people, most of the time feel that they have a problem.
People like to complain, too.
Understand this and you have struck gold. People don't usually know what they want until you give it to them. Sometimes you need to draw on your creative juices. Also, you might want to spend a lot of time going through design iterations. Develop, test, change, test, change, test, change, and so forth.