I believe that endurance builds character and the reasoning that you develop in your mind for that endurance becomes your self-respect. And that self-respect is what brings clarity/humbleness in speech. Based on the circumstances that you are facing in your life, sometimes you may have to endure a lot of things. You have to develop a certain reasoning in your mind to develop that endurance. It’s not at all easy.
Different people develop different kinds of reasoning based on their brought up, circumstances or compulsions they are living in, or the kind of knowledge they have or acquired over the period of their life. Sometimes, reading about history or knowing about what’s happening around us can certainly help in developing that reasoning in your mind. The drive for this reasoning is that you need it because without that you have no endurance and without endurance you cannot live. So the desire to live creates purpose (or even the other way, purpose creates the desire to live) that will help us build the reasoning that will lead to developing endurance towards what we are going through in life
For example “I am living a life based on dharma” can certainly be a reason to develop that endurance. It need not always be based on a philosophy. Lets take the case of a janitor, if they think that they are creating a healthy environment for people to live, that itself will create a purpose in their life, which in turn creates the reasoning for endurance