The fallacy of marks excellence

I had been told by some of my fellow brothers and sisters, that I’m smart. Yet, this is so far from what I feel of myself. It is true that I tend to get higher points in my courses (either by easy course, extreme shifting of marks etc…), I find myself lacking in a lot of other area of life. I have brothers around me that have already started to strive for things that are not just academic related, but really work related, like starting to put lots of time into joining clubs and participate in events that would add to their resume. Yet, here I am, just trying to study and get high marks, when the truly intelligent are not focusing on it, but on things that will not only be more related to their future work, but is impressing everyone with it.