Unexpectedness

Last year, the practical reinventor went to rather a lot of trouble to use this horrible old bathtub that had been dumped in the backyard for, oh, about 10 years.

Our preferred crop: water chestnuts.
They struggled and died off, and we got busy, so they got left.

They're supposed to grow through summer, then you harvest the corms (the water chestnuts are a sort of root vegetable) in Autumn, then plant the next lot in spring.  Since we didn't harvest them, we figured they all died and rotted away.
Except they hadn't.  Some had started to shoot, but most were crisp and added a definite sharp crunch to a coleslaw.
We've planted half a dozen in new potting mix and hope for a larger harvest next Autumn.

If we remember to harvest them...