Violets Take over the garden

It all started with one violet out of the blue.

Where did it come from? 
Should we pull it? 
There is already a beautiful ground cover of little blue flowers here. 
But it is so pretty.
After all, it is only one violet plant.

The next year...
Wow, look at how many violets we have here.
Maybe we should pull them out.
I really like the blue flower ground cover, but they are diminished.
We'll wait and see if they come back next year and decide.

Next year...
The violets have taken over the garden!