When I first started gardening addictively, I created a long sunny border along my driveway. To provide a temporary edging for this garden until I could find longer-term edging plants, I transplanted wild violets (dark purple and pale blue/white) from the many nearby places where they grew wild. Each tiny transplant quickly grew into a strapping specimen.
Both the flowers and the foliage of the wild violets were lovely at first. In addition, they had such personality: puffing up happily when their water needs were met and flattening out completely when they needed water.
But soon violets were popping up all over my new garden, competing fiercely with all other plants. So, with some regret, I decided to remove them. However, each time I removed a violet, a ring of tiny seedlings surrounding the displaced plant would quickly rise up to replace it.
It took a lot of time, vigilance and determination to remove all the violets, and some sadness too because they were so pretty. But now they are all back where I got them in the first place, seemingly happy to be home.