That’s a fair question and I admit that, according to dictionaries, it’s not even a real word.
It does characterize my own aspirational state of mind. I want to be curious about many things and other people, all of the time. But also, it’s meant to be motivational — for myself, as a writer.
Why is wonderful a word and curiousful not? It seems unjust. But it seems also to point to a source of beauty inherent in the language — its organic and haphazard development. A language that was entirely regular and completely “built out” would somehow offer less to its users, say less about its creators.
Without ever having heard the word before, you knew or could guess what I meant by it.
“Wonderful and very curious”, he said, trying to find the right words to describe her.
“Why not curiousful and very wonder?” the AI asked.