Some folks here have reported it can happen, but it's very rare maybe once every blue moon.

I personally discouraged its sale in my neighborhood supermarket maybe 10 yrs. ago. Was going for $12 for a leaf that would almost never grow a plant. Pot full of roots, but no plant.

In order for it to actually grow into a plant, from what I understand, a bit of the meristem tissue from the old stem needs to be present. I could be wrong. I have never attempted a leaf rooting, though.

I started a kerrii single leaf 2 years ago. I took a small piece of stem with the leaf. It took a year to get my first set of leaves. Today it has a total of 5 leaves not counting the original. A very slow process but it does work IF you have part of the stem.

Thanks for all of your replies. My understanding was in line with what was explained here, that you needed at least a small piece of stem for it to grow into a big plant. I'm curious to learn more about this now. Does anyone know the horticultural explanation for this, or any keywords I can Google? My Google-fu is way off with this search and I keep turning up nothing.

@lmontestella - Those are such obvious search terms that I'm convinced I have a serious case of stupid today. Thanks for that suggestion, I'm off to learn something new (assuming my brain is finally awake). ;)