People value intelligence and will apply that label to themselves even if it may not be true. It's a hard thing to measure though IQ does it reasonably well. To those who have a high IQ: what is it like? Can you pick up any book, read it, and understand the gist with minimal repetition? Can you infer solid and accurate conclusions based on a small amount of evidence? Is any subject or discipline up for grabs or do you have to have a keen interest in a particular field in order to flourish? What is something you are able to do that you know is because of your intelligence -- the proverbial 1,000 pound deadlift of the brain, if you will.
There is no point to these questions other than curiosity.
I tested high but I don't think of it as "smart", it is more like "capable".
I read for recreation and it's easy and relaxing. There's not much to say about it. It's pleasant and healthy to read. A person who reads enough books will become "smart" because they're accessing experience that is otherwise cut off to them. The accumulation of the neuron connections that command the relationship between two ideas is practically definable as "intelligence". Low IQ people who are knowledgable can come to any conclusion I might come to by different means.
Nothing in this world is too complicated, it seems complicated when we look at all the overlapping and interacting layers of simple A/B logic, but when you examine some little mechanism in a vacuum, it is simple every time. A relatively low IQ person simply skips fewer steps when they examine things. With a disciplined mind they can run through things at their own pace and come to a rational solution. The difference is that a high IQ person will make many assumptions along the way and get there faster. If we examine an assumption, we see that is simply a small set of intellectual connections that have been conglomerated into a block for easy reference. In effect, the high IQ person is compressing data to stream it faster.
"But You_Are_Based, wouldn't a more intelligent person skip less and not more?" Well, it depends on the needs of the moment, on the context and our motive. In 99% of the every-day situations we run into, speed is percieved as intelligence whereas a meticulous thought process is percieved as "slow".
I infer and deduce people's disposition and motive accurately, which helps me appeal to them when I want to, but since I'm not an agreeable person it also results in me treating certain people very rudely, even as strangers. I make assumptions and I tend to trust in them unless it results in a discrepancy that proves me wrong. I'm a little socially impatient. People play games based on their own simulations of my rationale, and I see it happening in real time. I either have to wait for them to complete their performance or interrupt them because I already know what they're trying to accomplish and why. I have wronged people before by underestimating them and overestimating myself, but when that happens and it is demonstrable to me, it makes an impact on me and affects the assumptions I make in the future. I.e. I am exactly the same as everyone else.
Something I can do based on my intelligence is to produce a long-form text narrative (anywhere from an essay to a novel) with very little prompt. It's easy for me to simulate a living world with individuals that have their own agency and to communicate it in English. It's easy for me to parse out custodies of events and work cause-and-effect to the point of Butterfly Effect. It's easy for me to tell what a person is like from how they communicate, what their motives are, where their lines in the sand go, etc. It's easy for me to take the prose of some successful bit of rhetoric and smush a different topical/narrative aim into that template. It's easy to debate in favor of things I don't believe. It's easy for me to disassociate from myself and play or write characters that don't share my natural idiosyncrasies.
I am not a lonely person. I can tell what people need from me and if I care about them I will provide it to them. My best friend is fearsomely intelligent and we are always putting the other on a run for his money. I'm friends with people who are not very intelligent, but who are better persons than me. I like people who participate in the reindeer games and I will put aside all my tightassed bioandroid bullshit and all my bigotry to play reindeer games with them. I like people who create art and who appreciate the art that others create. I like musicians who can sit down for an improvisational jam with me. I like people who are competitive in strategy games. I like anyone who second guesses the motivation behind the delivery of information they've recieved from someone else. I like talking shit with strangers about society, and then saying bye and never seeing them again. I like more people than I hate, and I say that as an avowed counter-semite and dissenter under globohomo.
I forgot to mention competency ceilings, like math. I don't think there's much to say about it. The math in school was easy because a person was there to tell me what to do and how, and they drilled it for repetition. The repetition being so important just goes to show that the process is not actually dependent on IQ. But if we take it far enough, we get to a point where our ability to memorize some algorithmic ritual is insufficient for the ritual, and there we see our ceiling.