mystery bloom in Ohio

Friends,
The mystery is not the name of the bulb–it’s N. bulbocodium, on a VERY short stem.  The mystery is why it’s blooming so early, and also how did it get there?  The label on the pot lists some other species which I’ve had since 2007 and has never bloomed.  So, was this bulb a small bulb collected with something else, or did a seed fall from an adjacent pot into this one and has now grown big enough to bloom?
Whatever the origin, it’s nice to have a flower in bloom.
Mary Lou