Vipers bugloss

Sometimes I just don’t understand plants and gardening. I planted dozens of vipers bugloss seed (aka echium) in pots, and the only one that came up is this one, which I didn’t plant.
Some gardening this morning, mainly weeding. Then off to Clifton, first a haircut, then the Oxfam shop. Seemed to get quite a lot done today - did Teen and Young Adult books too, and a display of toys. Also bought toys to thank my neighbour’s children for looking after the cat and watering the garden