When I was a kid, I used to wonder at how our dad used to treat me and my older brother. I couldn't understand why he treated us so harshly and had these outbursts of rage all the time. I withdrew to my imaginary world of video games, only realizing the truth after moving out – he couldn't fix any of his problems any other way and so it became the go-to solution for everything.
I actually found myself becoming the exact same way: stuck in a mental and emotional rut that made me overreact and misbehave all the time, just like my dad. It's only through constant introspection and a desire to hear criticism that I finally set myself straight to become sociable and approachable.
What I termed mental illness in my dad were actually behavior patterns that served as adaptations to his life circumstances. I developed behavior patterns as well, though mine were that of avoidance and submission. We constantly adapt to how life and other people treat us but none of those adaptations are necessarily illnesses. As you grow up, you will necessarily have to adapt or die.
Those adaptations are ultimately meant to help us survive long enough to grow beyond the initial situation. It's in cases where growth stops that we find ourselves stuck and unable to change our behavior, leading to suffering, awkwardness and stagnation. It's only through staying in constant touch with reality and reacting to it in a relaxed manner that we can ever become truly flexible in mind and heart, which is the core of mental health.
As the concept implies, adaptations are meant to be reversible. If your "mentally ill" mom is triggered by loud noises, then you adapt to be quiet. However, you should stop being quiet as soon as you're outside mom's earshot. When you keep being quiet even when mom is no longer there, then we can start talking about mental illness, which is best defined as blockage to growth, not any behavior in particular.
I'd like to point out that I'm not a mental health expert save from observations I've done on myself and others. What I am an expert in is stating the unspoken truths – people think they are mental health experts and are too critical of others. We're doing better than anyone else gives us credit for, and so if we listen to these layman mental health experts who constantly nag us, we start doubting ourselves.
A common pattern I discovered with layman mental health experts (i.e. everyone) is that they constantly judge everyone around as crazy, silly, foolish etc. I think this is because attaching these labels to others makes the person protect his own ego and dispense with personal responsibility. It's very easy to blame others and criticize them for perceived flaws because it requires very little mental energy or investment but is very hard to defend against.
That being said, you should learn to recognize the blame game, that is, an attempt to blame you for something that happened or even something that you 100% did. There are always extenuating circumstances that the critic should note and mention to make the criticism fair; if that doesn't happen, don't accept the criticism. Do not allow yourself to be a verbal punching bag for people who think themselves infallible and mental health experts. Simply question their self-righteousness and the ability to make such definitive statements.
Calling someone a retard, an idiot or a moron is a mental health diagnosis. Those three terms signify a person that has a low level of mental and emotional adaptation to the environment and can only be made by a qualified mental health professional. I estimate that the real of number of retards, idiots and morons an average person meets is about 1 a year or lower, though you wouldn't think it based on the number of times these insults are uttered.
Another problem with my dad is that he never told us what happened in his life, which made us judge him way too harshly. Had he told us what horrors he endured, it would have made us more sympathetic and also better prepared for life. We would see how easy it is to lose the circle of support and slip into misbehaving if we don't have someone to keep us straightened out.
Telling the truth about what happened to us should in the long run help others understand us and forgive us for misbehaving. However, we can't do that if there's no willingness to listen or understand from the other party. This type of honesty also implies that we have forgiven ourselves. For me, that was the most difficult part – I had to realize it wasn't my fault for anything that happened. As soon as I forgave myself, I moved out and on with my life.
Do not judge others too harshly but also don't accept any kind of unfair criticism, especially when it comes to your mental health. If you are constantly trying to make yourself feel, speak and act in a more genuine manner, you're growing, as slow as it might be. As long as you're growing and learning, the adaptations are just a unique flavor to your personality that are somehow helping you survive. If someone does try to make you doubt yourself because of your adaptations, you can simply reply with the subtitle of this page: "Everyone is crazy except you."
Do not diagnose yourself as mentally ill. This is key to staying unscathed mentally and emotionally in the long run. If someone tries to convince you you are mentally ill, always question the person's credentials i.e. ask: "Are you a mental health expert?" If they aren't, DO NOT listen to their layman diagnosis. Otherwise, you risk fixing what isn't a problem to actually cause a problem.
This idea of withholding judgment on mental health issues has been established as "Goldwater rule" that states mental health professionals should never diagnose public figures they've not examined. So, even a trained professional can make a mistake when estimating someone's mental state if it's done hastily and at a distance, let alone when done by a layman who just wants to see you hurt and in anguish for a cheap ego boost.