It's a dream... the only things that are bulletproof are the things you expect to be ... any RC can fail, and any RC can work, that's why its always best to do at least 2 RC's every time you think of it IRL. Personally I do the nose pinch then look at my hands, and every time i see a mirror i examine myself and my hands. Also, any time you think "that's weird" or anything similar in real life, that is the perfect time to RC because lots of weird stuff happens in your dreams. When i first saw snow on the ground I did a RC and realized I had forgot my back pack in a lecture hall, possibly saved me from losing a laptop haha, real life applications for lucid dreaming.