Getting good at Spanish

I speak reasonable Spanish. But getting from reasonable to good is something that I'm finding really time consuming.
I'm talking about moving from B2 to C1 CEFR levels, and specifically about spoken Spanish.

I know there is a trend to talk about language learning as an easy process, and in fact there is a common believe that Spanish in particular is an easy language.

What a load of dogs dangly bits.

This is a mistaken assumption, which I am about to shed some light on, and if you are sitting comfortably, I'll now tell you why and how it arose.

Spanish grammar, initially, is fairly straight-forward. It is not difficult to learn to construct (albeit simple) but mostly grammatically correct sentences fairly quickly. This will enable you, dear reader, to start speaking fast if that's your thing.

You won't understand the answers, but that's fine. Comprehension is a whole different skill set.

So you can construct largely grammatical Spanish sentences after a short(ish) period, and conclude that Spanish is easy-peasy. Tell the internet. You can't understand, but hey, that is because the Spanish speak quickly, and that isn't speaking anyway.

I'll give you that. We are talking about the spoken language, and people will often speak slowly for you, if you ask nicely.

But once you've got beyond the basic words that need to be learned, the amount of vocabulary that you need to learn, to become GOOD not REASONABLE increases exponentially.

Here is an example. I was doing a language exchange today, and the subject of bull running in Pamplona came up. Personally, I think you must be deranged to place yourself in front of 1000 pounds of angry prime beef, but that's not the point of the story.

Do you know the word for 'bull running' in Spanish? Me neither. Well, I do now. It is 'encierro', but it neatly illustrates the range of vocabulary that comes up in a normal conversation. This was on top of talking about people (mainly from Australia apparently) who climb to the top of the tower in the central square in Pamplona, then leap off, and are caught or not by the crowd underneath.

Extra words needed, fountain, climb, jump, mortality rate. Do you know all these words in Spanish? Do you consider them 'difficult'?

They are not difficult, or unusual but you need to know them all actively (as well as passively) to be good at Spanish instead of reasonable.