Language and refinement of thought

Today something weird happened to me. It was the first time in my life when I had in mind a concept, a concept in English, and I could not translate it in my mother tongue. It's a dilematic situation: I feel I fully comprehend the meaning of the word, that I understand it and I know how and when to use it, I know how to explain its meaning in Romanian (in a phrase), I know synonyms in English, but I just can't find an identical meaning in my language!

For the first ten minutes, I felt I had the translation on the tip of my tongue. The explanation was, of course, that because I haven't had used it in Romanian for a long time, but I definitely had used it in US, it was harder to remember. It was just a matter of memory.

But after the first ten minutes, I realized that the issue is deeper. I asked my parents for the translation, I searched in four dictionaries: I was unsatisfied, because the translations found weren't identical, they didn't express exactly what I thought that concept expresses.

There is a saying that crosses my mind. This could be the explanation! I heard a long time ago that English is a complicated language, because its concepts are more refined. For a foreigner, English-speaking people have three words for the same meaning, and there seems to be no difference between them. But for a native, there are fine nuances that make the difference. Since I learned German, I know it's even more true for German language.

But what if our thought is conditioned by the language we use since birth? More specifically, what if the limits of our thinking are drawn by the limits of our mother tongue? If English natives are raised and their thinking develops within the English language, doesn't that mean that their thinking is more refined and more evolved than ours? This would make a whole lot of sense, especially if you appreciate Anglo-Saxon and Germanic thinkers. Weren't they the most rigorous and precise thinkers?

But if this is true, what happened to me? How was it possible that by learning how to use a word in a foreign language, I learned some meanings difficult or even impossible to express in my own language? (Hehe, in the former sentence I initially wrote "hard" instead of "difficult". In Romanian, we use the same word for both meanings after all. Not counting neologisms. Constant refinement?..)

I have another hypothesis: maybe when we learn a word that is not in our mother tongue, we invest it with meanings that we think are fit, according to the instances where we use that word and people understand. If I say "boole" every time I want to say "bowl" and I act accordingly (I'm taking the bowl of soup in my hands), people get used to me saying "boole", and, if I don't know I'm pronouncing it wrong, I will believe that "boole" is the word for bowl and I therefore invest "boole" with a new (not very refined!) meaning, meaning that is recognized only by me. What if that refined meaning of the word I cannot translate is only in my head? What do you think?