How can RC fail in a dream? I did a nose RC and couldn’t breathe through it in a dream! how can it be?
Every now and then I’ll have one that will show that I’m not dreaming, but often times doing a second will fix the issue for me. I think it’s just a matter of our minds expecting it to fail, but doing one allows us to doubt it enough for the next to pass.
RC’s are not the end of the world. They are still to be applied in a dream, and the dream is the realm of expectation, so you must be wondering if it’s a dream if you want that RC to work, or you’ll get the results of when you’re awake.
I used to get the same thing, doing a RC but clinging on to the idea it was reality, and most of the time it only confirmed my beleief (gotta thank the nose RC for the times it didn’t); anyway, by being stubborn and doing it enough times, it would eventually fail (telling me I’m dreaming).
The key here is being confident enough in the dreamstate that you do several RC’s, and you are confident about the results.
I actually did it 2 times(RC) and it failed(maybe because I belived it’s reality) and I asked my DC mom and she said:“maybe yes and maybe not, don’t you get it?”.
But still nothing.
What you expect to happen, happens. If you think “Oh i gotta do this boring RC that never works” when you do it IRL, you will do the same in the dream and since you expect it not to work, it wont.
Exactly ! I used to have the problem as well ! I thought something similar IRL, and then the same happened in the dream and I was so much relying on it that even when a DC told me I was dreaming I was still not conviced about it. And I had just fly in the sky.
Sometimes your mind is not in the mood. But rather than relying on RCs too much, you can try to adapt how to become lucid : for example if you try a RC that fail, try to do something else like remembering your real life, or anything else that you think can make you realise that you are in a dream.
When I had this RC problem, I read about other RCs and I got to use them in dreams. The most efficient so far is the “look at your hands” one, since I can never count 10 fingers.
I also adapted a RC, the “finger through palm”. I had this problem : I did it too much IRL, so in my dream I knew how it would feel and after a while, my finger would just touch my palm and the RC would fail.
I changed it so that I focused not on the idea of touching my palm, but on the idea of letting my finger go right through my hand.
The result was that in two normal dreams, my finger was pushing the back of my hand like if it was cheming gum, I could see the nail right through it 
and then I realised I was in a dream.
There is a lot more to discover, don’t worry, you’ll better understand what you really think of RCs and you’ll be able to create your own and also rely on something else. Try to be lucid without thinking “oh wait I have to do a RC” will also help you.
I forgot for a while about RCs, and it’s later on that I could use them again, without pressure 
For me it was the other way; I did the Nose RC and I could breathe. But I didn’t become lucid thinking “it is normal”.