Marta, yes, I agree, I was off the mark when when I said writing for yourself is only a journal or diary. You absolutely can write anything for your own pleasure. (I also don’t like to journal. Unless I plan to use it later in a story.)
But I think most of us would like other readers to like what we write also. And there in lies the thought for an audience. Obviously, we need to use proper spelling and grammar, and some sort of story structure, which is more for the reader than ourselves. When writing a note for ourselves we don’t concern ourselves much with those.
When I write humor, I definitely consider the audience. Is it funny or entertaining to others, or just me? Will people, get it? I am often surprised at what turns out to be popular. But there is usually some thought for the audience.
I highly value originality, and usually ignore any writing advice that uses formulas or rules to make writing more popular or mainstream. But I am not courting a writing career, so I have that luxury.
I suppose it all depends on the writer and what they want to accomplish with their writing. If it is therapy, then it is a far different approach than writing fiction, or an essay.
I will stop now before I babble on indefinitely. Thanks for indulging me.