We regret our loss.
We don't realise that it takes the loss of the old in order for the new to arrive.
Why have people always made sacrifices?
For example when laying the foundation of a new building, or before starting a new venture?
They do this because the new requires the destruction of the old, sometimes only partially and sometimes total destruction.
The more we are prepared to let go of the past, the more the new future can replace it.
However, when the new future arrives it appears in the form of an enemy, and not in the form of our wishes coming true.
It appears as an infringement and the destruction of our ideals and wishes.