This is what I think about themes.
Know what the theme of your story is, if you must. But do it for yourself. Because everyone else will put their own themes on your story. The woman who just broke up with her boyfriend, the father that just lost his job, the academic who has something to prove to the world. They bring themes with them, and they’re always willing and ready to stick them to your story like flypaper. So in the end, maybe it’s better you don’t worry about theme too much, and just write your story and see what happens. Themes I feel come to the surface when they’re good and ready. When you’ve written enough of your story and given it enough weight, that it buoys its themes to the surface.