We have the most beautiful double-flowering cherry tree in our backyard, one that produces blossoms so huge that everyone marvels at it. When Shawn and I put an offer on the house, in the spring of 2012, it was in full bloom and seemed to take over the yard. A year later, at Austin’s birthday party, the kids ran under the tree as pink petals blew everywhere, almost as though they were running through a snowstorm. At some point, Shawn told all the kids to stand under the tree and then he shook one of the branches, producing a million loose petals. A dozen tiny voices screamed with joy, and…