Tangential Examples

At the Thanksgiving dinner I was invited to yesterday, one person brought up how she thinks some of the things professor mentions in this one class are "too" tangent and uninteresting--she explained that she doesn't like it when she has to learn something that seems irrelevant to her, such as "using this concept/ideas/formulas, we can learn that there may be a star far, far away that is yet to be discovered." Indeed, the tangential topics in math/statistics classes work and don't work depending on the students' interest. It is upon instructor's discretion to decide whether certain example will help or hinder learning.