Multi-faceted words

I don't now if I can make you see numbers in a new way, but I do pay more attention to words and the way we use them.
It strikes me that words have more than the dictionary meanings, more subtle nuances that one has to have an intimate connection with the language to really understand. Still, sometimes we can get a glimpse of that if we pay attention.
Here are 4 examples that have the same meaning and in 3 of the cases even the same form, but different nuances.

First (I have already mentioned that another time) "illusion". In Romanian as well as in English, it means something unrealistic, that can never become reality, a mirage. In Spanish, I think, it does not have this nuance, right?
Second: "didactic". We wrote a conference article in our Comenius project last week and it was the English partner who "polished" it, of course. He told us he took out the word "didactic" and replaced it wit "pedagogical" because in English it has a strong pejorative connotation. It can have that in Romanian too, but very seldom and a bit forced.
Third: "compromise". This word has a strong negative meaning in Romanian and maybe in English too, as well as I can tell, but in Spanish it has a totally different meaning- commitment, right? Please correct me if I am wrong!
Last, a word you use often: "stubborn". In fact, it triggered all this silly post. For us here, being stubborn is certainly not a quality, and it's a feature we always nag our children to drop. Tell me about how it's seen in your place, if you want- I'm curious.

One can find out a lot from just a word, and this is amazing for me.
Sorry if this is childish, I'm lazy today and just letting my mind wonder.