I actually just had a moment like that (sudden lucidity during a dream) in my last sleep. Probably would have lost that memory entirely if this comment hadn’t reminded me. Even still, I can’t remember the context, just that something was happening that was mildly annoying and I realized I was dreaming.

I just said, “wait a minute, this is my dream, I’m in control here” and then I think the dream shifted into something else or something because the memory fragment ends there.