A fast answer to a hard question is usually just a guess wearing confidence.
STILLNESS
STILLNESS
Hard questions are hard because they need information you do not have in the first second. Speed of reply says something about comfort and nothing about accuracy, and confident delivery hides the gap well enough that most people never check. The worse version is when you do it to yourself, deciding quickly so the discomfort of not knowing ends sooner.
Get comfortable saying that you need to think about it. Out loud, to a teacher, a manager, a friend who asked you something real. Then actually think, and come back with your answer later the same day. People trust the second answer more, and it is usually better.
When did you answer confidently without actually knowing?
Free, with nothing to buy inside it.