It occurs to me that the peculiarity of most things we think of as fragile is how tough they truly are.
There were tricks we did with eggs, as children, to show how they were, in reality, tiny load-bearing marble halls;
while the beat of the wings of a butterfly in the right place, we are told, can create a hurricane across an ocean.
Hearts may break, but hearts are the toughest of muscles, able to pump for a lifetime, seventy times a minute, and scarcely falter along the way.
Even dreams, the most delicate and intangible of things, can prove remarkable difficult to kill.