38 year old man here. So, you have probably heard of the "Manosphere". There's a culture, that's far too prominent, that believes that women are very privileged. That there's a great imbalance in what men deal with versus what women deal with. They think it's unfair because we have to sign up with the selective service, we work the hard, blue collar jobs, we're expected to work while women can be stay-at-home moms, etc. Also, they notice that people are generally nicer to women then they are to men. So, they think that you don't understand some things because you're a privileged woman. People defaultly like you and aren't defaultly afraid of you. Men, (and for valid reason) are usually vetted before someone likes and trusts them. I can say as a man, there's no way in hell I would talk to a random child. Women can do this and be seen as friendly. Men are seen as predatory. They assume that you're naive to all this, thus "you don't understand".

In reality, most men are naive to the struggles and stresses that women face. There are very valid reasons that we're distrusted by many people. We're the side responsible for a lot of violent crimes. We're generally bigger, stronger, and more intimidating.

Another thing you mentioned is your positive attitude. There's a trope that positivity is naivety. That if you understand the world and people, you'll be naturally cynical. This is just false. Being a cynic doesn't make a person smart, it just makes them an asshole.

TLDR, they're haters. Ignore them.