The phrase "gat knack of" implies having a natural ability or talent for something. However, the antonyms suggest the opposite - lacking skill, talent, or proficiency. Some of the antonyms for "gat knack of" include ineptitude, incompetence, inadequacy, clumsiness, incapability, and inexperience. People who lack the "gat knack of" may struggle to learn new skills or tasks, and may require additional training or guidance. It's important to note that, even though someone may not have a natural talent for a particular activity or task, it does not mean they cannot acquire the necessary skills and proficiency over time.