It’s understandable that people with large gardens forget some of the species they grow. I may also forget some because of moving them all the time from one container to another. In these situations, I use the method of ‘elimination’.
To start with, I knew it was a Lilium ;) First I flirted with the idea of being Lilium martagon. Later, looking at the grassy foliage, I thought without much enthusiasm about L. lancifolium ‘Flore Pleno’. Only when it got close to flowering I remembered I also had/have a Lilium pumilum.
Of course now that it is in flower, it doesn’t look like one that’s easy to forget…
Propagation: easy from seeds, bulb scales; bulbs said to be short lived(?) and edible/medicinal(?). It may be a while until I have enough to give them a try; for now I only admit to the fact that it is a tough one ;) And if it decides to be short lived this year, I hope there will be seeds.