According to Osho, attachment to painful experiences persists because we still crave the pleasure linked with them - the 'flower' we refuse to drop while trying to avoid its 'thorns.' Mind's habit of choosing and dividing keeps both sides of the coin in our hand, creating tension. When we see pleasure and pain are inseparable and stop choosing, attachment falls away spontaneously.
We hold on to hurt because we still want the nice part that comes with it; seeing they always arrive together lets us drop both.