There are many people out there who seem to lack the ability to analyze the consequences of their behavior, or to admit that they were ever wrong. There are also people who seem to be very bad at understanding what are their motivations for doing certain things. Not being able to look back at your own behavior and your own mistakes makes it nearly impossible for these people to grow.
I won't get into the argument as to whether these differences in self-awareness are biological in origin or due to nurture. It's probably some of both. Either way, even though this metric is multidimensional and hard to quantify, some people are definitely less self-aware than others. Just like some people are less physically fit than others.
In any case, the vast majority of healthy humans are probably more self aware than the vast majority of healthy crows, no?
[0] https://en.wikipedia.org/wiki/Stanford_marshmallow_experimen...
Intelligence is a far-cry from self-awareness. I once knew someone who would regularly (daily, for years), in conversation, cut other people off like they weren't even there to completely change the subject to their own preference. I once called them out on it and tried to finish my original point to the rest of the table. They yelled at me and demanded an apology that I would dare cut them off like that, that I would dare try to finish my own point.
I have several similar stories, but the rest are far too specific for the open internet.
Some people just pay themselves no mind.
Unfortunately, a lot of people boost their worth by degrading others, so to give that credit to those that they look down on would cause them a certain degree of cognitive dissonance.
It's hard not to notice that many people are... dumb, but content or happy. They don't second guess, they don't fret, they don't think much.
I really wish I could be like that.
I suppose it's possible to mistake low neuroticism for stupidity. And if you don't talk to dumb people (pick an IQ range below 100) very often you might not know their worries and concerns, especially if they're not overt about them as is fashionable for Lisa Simpson-esque individuals.
Still bad news on adjusting your base intelligence (apart from drastically down through damage), I don't know about adjusting self-awareness though I suspect it's a bit more mutable in good and bad ways (if only because related traits better understood are more mutable), but at least your desire to feel happier or more content more often is a possible state for you to achieve if you work at it. Some people will recommend therapy (surprised nobody has internet-diagnosed you with depression already), or meditation, or philosophy, or drugs (prescription or party), or whatever (I like the idea and research of gratitude journals https://en.wikipedia.org/wiki/Gratitude_journal but don't keep one), I don't want to recommend anything, just point out that personality and outlook is more mutable than something like base intelligence, which is good news for your melancholy should you wish to attempt change.
Of course it's not the only thing, and can be greatly mediated by other factors. From the book Age of Em, citing that and other sources, "people today tend to be both happier and more productive when they have jobs, autonomy at work, health, beauty, money, marriage, religion, intelligence, extroversion, conscientiousness, agreeableness, and non-neuroticism."
I brought up Lisa Simpson because there's this meme: https://flowingdata.com/wp-content/uploads/2008/06/lisa-simp... It's a popular take, but it's wrong.
On the other hand, small scale situations similar to what's depicted in fun-fiction like Idiocracy or other things keep happening, and the idea that reality is stranger and crazier than fiction holds true. I've joked that the 2020s are going to be the dumbest decade, and will require the dumbest people. Holding up well so far. Furthermore, even if we acknowledge that humans are intelligent, period, there is still great variation within humans. There is variation on every trait we can measure, self-awareness should be no different, the presumption that no one is more or less self aware than any other person defies reason. Apart from that, just observing people's behavior in a casual way I think it obvious that people vary quite a bit when it comes to self-awareness, both in general every day lives (which I can notice varies in myself) or in specific focused tests. It doesn't get better when you switch from casual observation and conversation to more detailed study, psychology and psychotherapy are full of strange and fascinating data (and not just of fundamentally damaged brains) which I think a model that assumes equal capacities in self-awareness would be hard-pressed to explain.