When your hand is frozen from ice exposure,
It feels numb and there is no pain,
But once you put the hand in warm water,
The unfreezing happens and now there is severe pain.
This is until the hand returns to room temp,
And then there is a new normal and aliveness, the pain stops.
The same applies to the frozen heart.
Even if an encounter results in you opening up and getting rejected,
Feeling the pain and anguish of rejection,
Is still better than leaving the heart frozen.
At least some unfreezing, feeling, and aliveness happened.
It is still sometimes better than feeling numb.
An endless revelation
Journey to the Abstract 
It is quite debatable based on how overwhelming certain emotions can be at certain times that they become unbearable and those times numbness would feel so much better.