I would suggest part of the reason lies in that when we were very young, we learned that our 'NO' can effect the moments that are about to happen. While our 'NO' does become part of the next moment, it cannot otherwise change the moment that already IS, because... well... it already IS!
But our 'NO' can influence and affect the moments that are about to unfold (and sometimes in the manner we desire).
I'm sitting in my highchair as a baby, mom pushing in the pabulum well past the point of full, now flowing over gums, hands, and bib, a pre-verbal inner resistance arises, hands flailing and pushing against, mouth clamping shut, face scrunching up, head turning away, squealing (like a baby)... and finally ... finally mom understands the unspoken yet unmistakable NO that is being conveyed by my sounds and actions, and she finally relents...
We have just learned the power of our 'NO'. And what a power it is. For in our 'NO' lies the power of changing the future. With our 'NO' we say, "I will not allow 'how it is' to continue", and we can begin to take action and move towards 'how it might be'. We start by using our 'NO' to affect our lives, by taking action determined by our desire for things to be other than they are, here and now. But then we get completely carried away. We become 'NO' addicts and we start to apply our 'NO' where it doesn't belong.
We do not simply use our 'NO' to effect change of the future, but instead use our 'NO' in places and situations where it is not only useless, but also harmful. Most often our 'NO' is simply an unconscious and ineffective resistance to WHAT ALREADY IS. Saying 'NO' to WHAT ALREADY IS, is in any other words, simply suffering. A 'NO' without action is simply complaining.
The most common form of useless 'NO' is our unconscious habitual mental chatter. "I wish things weren't like this" "This is so unfair" "Things shouldn't be like this" "Why me?" "I hate this". But that is just the beginning. Our useless mental 'NO' affects us emotionally creating an emotional 'NO' in the form of resistance or closure to feelings. "I' don't want to feel this" "This hurts too much " "I can't stand feeling like this".
When this emotional 'NO' also become unconscious and habitual, we are shut down to not only our emotional pain, but also to our joy as well. This emotional 'NO' then becomes a physical 'NO' where we are physically resisting and contracting, living in a state of tension and stress. We hold our breath as 'NO' to avoid feeling. We avoid eye contact as 'NO' to avoid vulnerability. We zone out, daydream, distract ourselves and live on auto-pilot as 'NO' to avoid REALITY.
Half alive, half awake, habitually resisting 'What IS' by thinking and feeling 'NO', we sleepily stumble toward our death.
In short, we live our lives in a state of unconscious and habitual mental, emotional, and physical resistance, avoidance, and denial in the shape of our 'NO'. OUCH!
What to do?