I can pick up a sense about someone, by the way they act or what they say (or don't say), but I'm not a mind-reader and don't know what they're feeling unless they tell me.
Growing up it was almost expected that I was supposed to "know," so I was always guessing and living in anticipation of everything, and of course if I read someone incorrectly it was my fault. And it kind of screwed with my head because I thought that's what people did, so I learned not to say anything, but then I would also be disappointed when people weren't "reading" me and didn't act the way I liked. And if they were direct with me, it would freak me out because I wasn't used to that, either.
Never really learned to say what I felt - or even that I had a right to say it - until I was an adult, and even then it was a learning curve. I've even been called on it a few times by trusted friends, who make me feel safe enough about it to acknowledge, "oh yeah, you're right." As I've gotten older I think I've gotten much more bold in my directness, and in doing so I'm also noticing 1) I'm more and more comfortable with other people who are direct, 2) more aware of how much people aren't that way, and 3) more aware how some are taken aback by what I say. And I'm not even saying anything unkind, just speaking straight.
Makes it so much easier though than to try and "read" each other.