Sticking to your own belief, regardless if it is by profession or through personal reasons is something no one can take away from us. Personal philosophy does not need to be commercialized to prove that we are right. Our own theories are based on what we have already proven to ourselves and that alone is enough to stand by them. Unlike many, one’s philosophy does not need to be adopted by another. Personality and outlook of two people are different and hence will carry different philosophies as well.
Compare yourself with another person. Or better yet with your brothers or sisters. While you all come from the same parents, your values and personal beliefs will not always coincide. Experience and beliefs based on what you see in the course of your growth build different perspectives and apparently you will live on your own beliefs separately. Whatever principles and beliefs you may have does not always become logical for them since you both have different perceptions based on built philosophies in life.
To illustrate, just compare careers. If one follows a routine desk job, the other may want to follow a different perspective like perhaps a more people-oriented path such as politics or sales. Some call it rivalry while others just want to discover new ways outside the traditional and proven methods. It is all about building on new philosophies which are not proven yet. These are normally cases where a person wants to prove to himself and to others that other personal philosophies can make or break what they want to develop.