Maybe your native language has metaphors similar to English, or maybe your friends are better at learning English than my friends. :P But my point is that man

Maybe your native language has metaphors similar to English, or maybe your friends are better at learning English than my friends. :P But my point is that many metaphors look "natural" only after you learn it: you have to memorize them, and you think it's natural only because you've been doing it all your life. E.g., "hot-headed" is a decidedly English metaphor. In Korean, "his head is getting hot" would mean he's getting annoyed/angry at the present situation, not that he has a propensity for getting annoyed in general (which is what English "hot-headed" means). Similarly, English "cool" doesn't just mean "the situation isn't hot."; it also implies a positive situation. In contrast, you can say "The show only received a lukewarm reception.", but you can't say "It's OK, he was lukewarm about the mishap." As another example, in Korean, you "turn blue" when you're shocked/aghast, not when you're gloomy. All this stuff is basically a minefield of subtle misunderstandings.