Struggling to keep up with genderized speech

Of all the things that amaze me about fluent Hebrew speakers, I think what amazes me the most is how people always automatically know the gender of the object of their sentences. When speaking Hebrew, you have to be constantly conscious of gender. Everything has a gender - nouns, verbs, adjectives, pronouns, even words like "it" and "this" and "will be". everything. so when I speak, unless I want to sound like an idiot who only speaks in the singular masculine present (which I don't), I am always forced to slow down and think for a second - ok the object of my sentence is future female plural - and convert all the other elements of my sentence appropriately. but it just amazes me how Israelis just do it so naturally, automatically, they just KNOW the gender of whatever they're talking about, always. But when you're learning Hebrew they tell you, there's no way to know the gender of anything except for just learning it - memorizing. there's no trick. sure there are certain letters that make a noun more likely to be male or female (such as words ending in "mem" are more likely to be male and words ending in "nun" are more likely to be female) but a lot of the time, you just have to memorize. Like what makes a door feminine and a window masculine? Or what makes the word for "breasts" masculine and the word for "war" feminine? It's not logic. You just gotta memorize. So it's quite impressive to me when I hear little children around me babbling away, converting all their adjectives and such according to the proper gender, I'm just like -- how do you KNOW?!! amazing. simply, amazing.