It's fine to write about characters who "do not relate to the world around them." That's what fiction is all about -- made up characters.
BUT, unless you're writing fantasy, the background, the "real" bits, the earth in which we live, must be accurate to carry your reader with you. I've made a comment on another post about boats. Do not make up stuff about boats, if you don't know what you're talking about. You lose a huge section of your readership. Similarly, the comment about oak trees in Africa. Impossible. This sort of stuff is so easy to check.
I remember I was collaborating on a James Bond book. While the movies are something else, the principle of Bond stories is that everything must be physically possible, albeit highly improbable. The first draft had 007 travelling by car and speedboat from central Australia to Hong Kong in a day. Totally impossible, but easy to correct. Similarly, details like which type of Hong Kong taxi (colours varied at that time with zoning) were wrong. Easy to correct. Either use Google or ask someone who knows what they're talking about.