Delightfully Unexpected, Find

For many years I have enjoyed searching for wild Orchids, particularly the Bee Orchid. I once found one outside of my office where I worked. It was growing in a small patch of uncared for grass and I was so thrilled.
Having joined in with the No Mow May, the grass was quite long. Today, I was astounded to find these two beauties in my back garden. In fact I was absolutely delighted and keep going out to have another look!!
I wonder why they suddenly appeared. Can anyone help me to understand?