But being able to picture in my own mind what life would be like in the Royal Household has helped me write some of the minor characters with more conviction. And I can "see" more of what Eileen gave up when she defected to Earth to marry for love. There are things she misses about her old life. Eileen prefers not to think about those things and people. (She was very popular with the ordinary populace for one thing. She also got on very well with the Household staff who appreciated her treating them decently. In fairness the Queen does too but this has not always been the case with the fairy royal family so when Eileen left, that opened up a huge gap for the Royal Household).
I hope at some point to write more behind the scenes stories which focus on life in the Household as opposed to life in royal government (which is where the quarrels between the Queen and Eileen are set) but I think, as long as you can visualise the world you're creating, then you will know what you need to put in to give enough information for your readers to "see" it too.
After all good writing is about communication and stories communicate ideas. So the secret life of your world can stay secret to you, your reader may never know most of it, but it is fun to create this and it is invaluable in helping you to write the stories you do want to write.