They just don't understand. Everyone can relate to this. You've been in situations that couldn't possibly be understood by anyone, except the one who has lived them. You.
A stranger makes a comment about controlling your children who has never raised a child, much less two or three. Your friends or neighbors assume you have a strange eclectic style when your clothing or furniture are a collection of hand-me-downs. Someone tells you that you're lucky to be in a situation that is your actually your greatest trial. Or they say you're lucky you aren't in a situation that is actually your greatest dream. You are chastised for something you didn't do. There are endless ways this can play out.
When you direct your first feature film, you'll be surprised to realize that everyone you know secretly thinks they could direct a film. It doesn't look too hard. They all have ideas about how they would have done it better. Maybe they even have some film experience. But they'll have opinions even if they have no experience at all. Maybe they witnessed a few days on set. Or perhaps they watched the film and thought about it for a few minutes during the credits. Regardless, there are assumptions and judgements all around, many of which are misguided. And all of which are limited.
Your primal brain sees being misunderstood as dangerous. For our caveman ancestors, rejection from your tribe could be life-threatening. That's not the world we live in anymore. Yet we still find ourselves feeling attacked or getting defensive.
Why do you need to explain yourself? Why do you need to be understood? You don't. What if you just let them be wrong about you? Other people can be wrong about you and it's ok. Really. It sounds basic, but our brains don't realize this. What others say about you doesn't tell us anything about you. It only tells us about them.
So when you are on the receiving end of unsolicited criticism or suggestions, remember this: You are the only one who gets to decide who you are. And what you decide is what you become. Other people will want to share their observations with you. But if their decision doesn't match the character you are creating, then they are wrong about you. And it's ok. It won't affect you unless you decide to believe it.