I'll tell you how I feel and I wonder if anyone agrees or disagrees.
In English, I feel that most words are tied to a distinct meaning. "This" is this, and "that" is that. This not that and that is not this. Such as a car. A car is a car and not a truck. A truck is not a car. But a vehicle can be a car or a truck. But a bicycle is not a vehicle. Anyway, most words are pretty distinct and do not cross over into another dimension.
But not so in Japanese! In Japanese "blue" can be blue or green! In fact, there are so many examples like this, where we would say they are not the same in English but in Japanese the words may not have as specific of a meaning as what they are translated to in the dictionary. This is a real source of frustration for learners of Japanese. That is why when you look up a word in the J-E dictionary you get so many words and many of them have very specific and distinct meanings in English.
Many Japanese words do not have English equivalents. What that means is that ideas and things are thought about in a completely different way. You will hear "shikaku." And you would probably associate it with the meaning "square." What it actually means is "four angles." So it can be a square or a rectangle. A real square is "mashikaku" but I've yet to hear that used. I look in my dictionary and it says "shikaku" is a square. So you confirm with the dictionary what it "means" and people are using "shikaku" for squares all the time and then one day somebody calls something "shikaku" that isn't square, it's a rectangle! And that's when you start pulling your hair out and going crazy.
OK, so those are just the nouns. I won't be going into "expressions" which are completely different from your native language!