I have almost always believed that being smart is a natural ability with which people are born with and that it had nothing to do with memory or knowledge.
But through experience I have come to understand that my theory was very wrong and that being smart has, in my unprofessional opinion 3 components :
It is my belief that being smart requires an average or a little above average IQ so that you can fully understand the issues you are being confronted with in order to formulate the appropriate solutions
This is a familiarity with someone or something, which can include facts, information, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject. It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); and it can be more or less formal or systematic.
Every day interaction may, to some extent, provide some degree of knowledge, it is up to you whether you seek it or not. I personally find the most valuable knowledge comes from other very experienced people (teachers, professors, mentors) or, from personal experiences gained from the trial and error method.
The trial and error method is a very powerful tool for gaining knowledge but really smart people prefer learning from other people’s mistakes and save a lot of time and resources in doing so.
I have many times overlooked this component and found it to be unnecessary nowadays that almost every piece of information in the world is stored on the Internet but there are times in life when one must react using only his or hers personal IQ, Knowledge and Memory, like exams, presentations or direct human interaction
So it is my strong belief that in order for one to succeed in life it is required to train all of the above components and not one or the other individually.
If you are looking for a Being smart guide, wikihow provides a great one right here. I warmly recommend you check it out.