Genes, DNA, and a nice surprise this spring. The Plum Pudding WAVE petunias that we enjoyed last summer whelped a nice volunteer crop of offspring. The petunias were hybrid so it's not surprising they would have unpredictable children. Still, as Kathy pointed out, one can easily see the color palette the experts drew from to make Plum.
The asparagus was not a surprise. Our bed has produced each spring since we planted it 30 odd years ago. Carefree and forgiving, I don't think you can ask for a more productive and easy garden vegetable. The bed is struggling now, suffering from root crowding by, and the shade of, the Dawn Redwood that I planted about the same time. I've ordered sets to start a new bed at the end of my new garden, well way from the redwood. It should last us another thirty years.