Can you regrow a plant after harvesting? Just wondering!!!

I recently harvested my purple kush/romulan. About 4 inches of the stalk was left sticking out of the soil and i noticed it start to grow fresh leaves. just for the hell of it
I stuck it under my 24 hour light and it started growing back.
This plant was from a seed i brought back from a trip, the only one of it's kind. I would have cloned it if i'd realized the other seeds were not the same, by the time i realized it was one of a kind it was allready budding. It'd be cool if I could just grow it all over from the stump.. could the lights going back to 24 make the plant go back to veg?

Oh mighty grow guru's help me in my time of need.

Absolutely keep it under 24 and don't over water.Remember it's still got a fully developed root system and nothing to support topside.
Up potting will help also.

thought that i would add in that its also suggested to try and leave about one third of the green growth on the plant when your doing this..

its called revegging mate, give her about a month and she will come back lovely..