Do you believe that it's good to have some mystery in your relationship even if you're already married?

Hello, Yes, I think there must be some mystery in the relationship, but I think it is quite to impossible after marriage and more so when you get more old in the marriage. It is because over the years you live with each other and you become like an open book to one another. And even if there is a mystery in the relationship, that too becomes a mundane thing, and the person gets bored with it.