I've never understand enough math to play with hardcore computer science (although I've love to and I tried) and I assume people feel very happier when they're good at what they want to do.
Views differ. There are as many views on this topic as there are smart people. John von Neumann took the position that being in the world didn't necessarily mean being of the world:
"You don't have to be responsible for the world that you're in." -- Advice given by von Neumann to Richard Feynman as quoted in "Los Alamos from Below" in Surely You're Joking, Mr. Feynman! (1985)
I happen to agree with that sentiment.
Also, when smart people decide to engage with the world's problems, they often get it spectacularly wrong -- example Nobel Prizewinner Bill Shockley's brainless campaign to make people aware of the imagined inferiority of black people.
Albert Einstein famously turned down the presidency of Israel on the ground that he didn't feel that he had a head for the world's problems. In my book, that demonstrated his genius.
I think smart people don't necessarily know how to competently deal with everyday problems, and very high skill in one area doesn't necessarily translate to even average abilities in any other.
It's best to just forget about being smart, and assume you're smart enough to do anything. The best way to be smart is just that it removes "I'm not smart enough to do X" from the way you think. If it does anything else, it's probably not good. It shouldn't make you think you don't have to try, it shouldn't raise your expectations, only just take "I'm not smart enough" off of the table. In fact, there's always someone smarter anyway. I find that, while keeping any sense of self-congratulation in check, without developing a superiority complex, I do need to keep in mind to a limited extent that I actually am smarter than a lot of people, so I do need to sometimes review their decisions and that some of the rules really don't apply to me. It's a fine line between that and hubris or narcissism, and it did take me sometime to come to that balance, going through "I'm better" to "I'm no better" to simply "I'm different, not really better or worse, but uniquely capable and in a position where I'll have to keep in mind that sometimes I'm wrong, but sometimes, the world is wrong." In the judicial system, you're judged by a jury of your peers. But there is an added responsibility if you are without peer. No one really has the insight to act as a check on your thinking, so you can be alone the way a pilot can be in a cabin full of passengers. They're not any less valuable than you, but they're really not in any position to review your decisions.
It's hard to explain.
Looks to me like you have something on your mind, or that you are discovering the moral responsibility that having a deeper insight might bring. When you get to this level (not hard) it's an individual choice though. You can use it for good, evil, or plain vanilla self-preservation.
Apart from "meds", I am not aware of any other way to improve your intelligence in everyday life. Experience, learning and age support your knowledge base directly - which in turn has the effect of making others think that you are intelligent - but those aspects don't necessarily mean you are "smart". In fact you'd be hard pressed to find two people that agree on what the definition of "being smart" is.
Smart can mean knowing when a fight is about to happen in a bar, and stepping back, making sure you still have your drinks. Smart can mean knowing what's wrong with a car motor just by listening to it. Smart can mean knowing when to pass, and when to score yourself.
Smart rarely means sitting on your arse all night debugging the same piece of code. That's when you start to imagine that a better person could have spotted the bug right away, or that there are coders who can write bugless code. And that's when the doubt creeps in.
Being smart increases others' expectations of you. They expect you to show miracles from time to time. Of course that cannot happen all the time. It is therefore necessary to develop an attitude such that others' perception does not affect you. It's what I call "I don't care what the world thinks of me". In my experience, in the absence of this attitude, smart guys can come under a lot of stress and make bad decisions at difficult times. (May be someone out here has a better way of dealing with it than mine??)
> I've never understand enough math to play with hardcore computer science (although I've love to and I tried) and I assume people feel very happier when they're good at what they want to do.
I believe two of your assumptions are wrong in the abvoe statement:
1. You really don't need to know too much math to play around with computers. When you come across a something that you don't understand you can always look it up (all thanks to Wikipedia) and learn it.
2. You become good at what you do by practicing repeatedly. Few are born with talented. Most of people become good at that they do by practicing it. There's nothing that can stop anyone becoming good at the skill they are interested in other than themselves.