Many people start lucid dreaming after simply learning that this is a thing and thinking about it. That’s how it happened to me: I simply started getting ideas in my dreams of the sort “hey, this is really weird, maybe this is the lucid dream thing I read about”.

It happens to me regularly now, probably something on the order of 1-2 times a week. However, I usually wake up rather soon after this realization, especially if I attempt to exercise any control over a dream, which makes it not very exciting, to be honest.