I know women who have been happily living in straight marriages (and considering themselves straight)and then, past 50, have "come out" as lesbians. There are a few here on the Forum also whom I know have gone from submissive to showing a strongly Dominant side - DungeonMaster6 is one - but with these people, they were sort of trained as r/l submissives, entered in that role, so it wasn't like "when I moved from fantasies to reality, it also switched from sub to Dom".