The word intelligent is being complicated by a lot people. They put a lot of meaning behind it, they treat it as a sacred word with lot of high expectations and qualifications. They say you have to be a graduate of Harvard or something to be labelled as an intelligent person, you have to become a lawyer or a doctor or you've got to have a Masters Degree. They say you have to study for 20 years and finish a lot of course if you want to become intelligent.
While some of those assumptions were true... but the real meaning of intelligent is simply doing the right thing. If you know what are the right things to do, if you make decisions well then you are already intelligent. You don't need to be genius or gifted or some kind of a phenom and describe yourself as a one of a kind human being. All you need to do is do the right thing. This thing is very basic, you don't need to make a lot of complications. The word "genius" or "intelligent" is so much overrated that it becomes intimidating for a lot of people.
If you need some money, what will you do? if your decision is to find work and not just to find work, you also make it to a point where you really have to work then that is already being intelligent. Making money by yourself and not being dependent to anyone is already being intelligent. You know the right thing to do, you put yourself in a good situation. What is more intelligent than that?
You have an assignment, you have a project, you have an exam tomorrow. What will you do? An intelligent person will simply do it. He will prioritize his responsibilities first instead of partying or watching tv. He will simply do it without any form of hesitation or excuses. He will do it no matter what. He will solve problems, study as much as he can and even cut sleep just to get things done.
You are competing next month, what will you do? there is no complicated analysis needed here. You'll just simply work hard, eat right, train hard and do the necessary things to make you prepared. It is very basic but a lot of athletes can't do the right thing, they were bumming around, they were preparing themselves to fail. The task is not easy but very simple yet they were complicating it.
Being intelligent is very simple, there is no Einstein mentality needed here. All you need to do is act and make good decisions. It is simply putting your life in a better position, it is just doing what is needed and being responsible in your life. It is making sacrifices if needed, prioritizing the things that are must. Bettering yourself everyday and having the mentality of getting things done as quickly as possible.
Anyone become intelligent, you don't need to be a graduate of a well know university or something. Just do the basics, make positive moves. Look for the things that are needed to be done and do it right away.