People are inclined to desire proof of theories if they have developed a certain philosophical style when they are quite young. It is a style that questions the authority for things, so that they can hold fast to what is good. Regarding mathematical proof, this author argues that it is only those who are prepared to take their own authority for knowing what math is about and what philosophy is about who will want mathematical proof. Others will be convinced by noticing that something seems to work and by being told by other people that it does work. He states that putting "Prove Pythagoras' theorem" into a syllabus is not a reliable way of ensuring students understand the purpose of proof: all assiduous students might do is learn a proof of Pythagoras' theorem, for no particular gain. However, if students "do their own maths" by exploring problems and coming up with results that neither they, nor their teacher know are generally true, then they have to prove them.