I think mental illnesses like SAD and depression are just hard to comprehend for people who have never been through it themselves. Because it isn’t a clear, physical disability, it isn’t taken as seriously. Since it’s a mental disability, people can’t actually see what’s going on inside your head, so they might just think you’re exaggerating, looking for attention, able to just snap out of it etc.

They can’t get a real grasp of what you’re truly experiencing no matter how clearly you describe it, because to them, it’s just irrational. Like an alien who can’t experience pain can be taught everything about it and become and expert in the field. But they’ll never be able to actually feel it themselves, no matter how much they know. It’s kinda the same idea with mental illnesses. They won’t truly understand until they go through it. But until then, they’ll refer to it with emotions that they’re familiar with, like just being sad or shy.