It's all about positive energy.
If you have a desire and it's of a positive nature, then how can it manifest while you hold onto or experience negative energy.
It's like saying when you're a millionaire, then you'll be happy, I doubt that would ever happen, for it's in the moment that the emotion, desire and intention must exist.
You change the now by changing the now.
You have to accept everything you have good or bad, because it's all good, even when it seems bad.