How do inferiority feelings really form in the first place? We all compare ourselves and the results of our efforts with everyone else – we do this from at least the age of 18 months. It is a built-in reality checking and learning mechanism. It has its uses. The thing is, we see ourselves fail in some regard where others are succeeding, and conclude we are doing something wrong (correct), but then further conclude this situation will be persistent (and that's jumping to conclusions!).
What are we doing wrong? Very often, we are simply dwelling on the negative (what we don't want) instead of the positive (what we do want), so our efforts start to slip compared to anyone else who isn't dwelling on the negative in a specific situation we care deeply about. The possibility that there may be something wrong with us on a fundamental, unchangeable level compared to others is what seals the deal. That's
really something we don't want, because the implications would be so severe. That becomes another possibility to worry about, and so we begin to feel inferior.
Apparently, subtle things like body language and tone of voice begin to display weakness and submissiveness to others whenever we feel really down on ourselves. This makes matters worse, because others pick up on this and their own reactions are affected, often without them even being consciously aware of it. So, fears about inferiority begin to create experiences that only reinforce the fear, until we eventually basically brainwash ourselves into this hesitant, self-doubting, anxious state where we see everyone else treating us like second class people and we act more and more like it. To make matters worse, we can't help but eventually feel defensive and start to compensate for it by pushing back in various ways.
One way to stop this, I have found, is to imagine what would happen if I was literally the most powerful person on planet Earth, like Superman on steroids.

What if I could snap my fingers and instantly create anything I wanted? What if I was incapable of ever failing at anything? What if I could simply will annoying or intimidating people out of existence?

(please remember this is a playful exercise in absurd imagination, just so you don't worry, lol)
Would I really want to be able to create whatever situation I want with no effort? No – because that would be boring, there'd be no challenge. I wouldn't feel good about myself. All I really want is to be convinced I stand a chance of success with effort that doesn't exceed what I can do. Would I really be prepared to make other people simply vanish into thin air on a whim? No – that's a bullying, megalomaniacal abuse of power in my book. Have you ever been bullied or put down? Most of use have. Do you want to BECOME just like the people who did that to you? Probably not. It would also imply I had a horrible anger problem, wouldn't it? If I can't control myself, I can't control anything! I simply want to stop being so intimidated by others, so the playing field feels level.
However, if you were the most powerful person on Earth, you wouldn't have to be afraid anymore. Perhaps the only thing to be afraid of would be yourself.
This mental exercise reveals that what I really want is to be in control of
myself – to say, “No, I will not be controlled by fear, frustration or anger today, or focus on everything I do NOT want instead of what I DO want. I REFUSE to accept that failure is personal, or permanent, or pervasive. I do not want to stuff my own emotions down, I want to experience them and deal with them. I want to CHOOSE how I react, what thoughts I focus on, and what I do in this moment.
I want to exercise the right to be who I wish to be, rather than allowing my circumstances and other people's actions to define who I become.”
If I can do that, there's really nothing I cannot do. To realize I have the capacity to choose is very liberating. If I do not exercise that choice, I'm allowing myself to become a helpless puppet of people and circumstances. It's so easy to believe that we are helpless, though, isn't it? With so many other people believing the same and giving up or overcompensating (and insisting that this is just the way things are), we hardly have a legion of healthy role models. The trick is to realize we really DO have a choice – we really CAN have that much power.
Changing a mindset really is hard, but it is achievable with persistent practice. I'm still very much a work in progress, which is why this post isn't in the Depression Success Stories forum. I'd love to see anyone reading this go out there with their head held higher than before, and do something epic today!