Your mind usually won't become lucid on its own, even if the dream signs are right in front of your face. You need to train yourself in waking life to become aware when these things happen. Obviously since dreamlike scenarios don't often occur when you're awake, your best bet is to know what your dream signs are and imagine yourself becoming aware that you're dreaming after seeing them; or you can try becoming more aware when you're awake. Any time you're not aware of your environment is a missed chance to become lucid. Good luck on increasing your awareness.