It might relate to a fluctuating ego also — Andrew4Handel
If I remember correctly (it's been a long time) Freud's concept of the ego was the "I" who negotiated between the rude impulses of the Id, and the demands of the socially oriented Superego. The Id wants what it wants when it wants it, and the Superego is the nagging voice, sometimes shrill, of what we OUGHT to do, because that is what is appropriate, proper, right, good, nice, etc. Id, Ego, and Superego come into conflict because we are social beings, and other people (who also have Ids, Egos, and Superegos) aren't going to let us have just what we want. You may want to eat all the cookies yourself, but so might several other people. If you do eat all the cookies (before others can make a play for the whole batch) you will be denounced.
Other people are not going to let us deviate too far out of the mainline without lettings us know that we risk becoming unacceptable, unlikeable assholes. The Superegos are oriented toward maintaining law and order, and making sure that the rules of etiquette are followed (if at all possible).
So, getting back to your question... why do our egos end up feeling like flat tires? It seems fairly obvious (but "obvious" doesn't mean "easy" or "simple"). If we are not aligned with the demands of society, we will get a lot of negative blowback. We may tend to be excluded from the group we identify with or are surrounded by. We are likely to feel degrees of exclusion, isolation, alienation, anomie, and so on.
Sometimes the only "true, right, and good thing" one can do is buck society but there will be costs, sometimes quite high.
The solution is to find a group with whom we can be congruent. That's not always easy; and besides, groups change, we change, and comfort levels can change.
On a personal note, I've found the most congruence with gay men, socialists, and other 'deviants'. Of course, the society of deviants can be very demanding too. Take the wrong approach and socialists can become very chilly, for instance. I'm kind of an odd ball so I get along best with people who are pretty tolerant.
When I have been immersed in unfriendly crowds (like at some workplaces), my ego has definitely suffered, and I didn't do well, flourish, perform as I might have, and so on.
If there is something wrong with you or me, it might be an unwillingness to align with the dominant paradigm. It may be true, right, and good to remain out of alignment -- but you have to find a way of taking care of your self, and not getting crushed.