"Whatever talents I possess may suddenly diminish or suddenly increase. I can with ease become an ordinary fool. I may be one now. But it doesn't do to upset one's own vanity"

This quote by Dylan Thomas talks to the idea of humbleness and the importance of not taking oneself too seriously. It is a reminder that no matter how skilled or knowledgeable one might be, those talents can reduce or increase at any time. It is likewise a reminder that no matter how gifted one may be, they can still make mistakes and be foolish. Thomas is cautioning against letting one's own vanity obstruct of acknowledging their own flaws and mistakes. He is recommending that it is necessary to stay simple and to not let one's own ego obstruct of recognizing one's own weaknesses. By doing so, one can remain open to learning and growing, and can prevent becoming too prideful and big-headed.