Ralph, Stamford asked:
Smoke from a blown out candle can be re-ignited, so why wouldn’t a snuffed candle pop back into life?
Essentially, the wick just isn't hot enough to re-ignite that wax. You actually need to get the wax hotter than the wick needs to be in order to smoulder. So after it's been smothered, it just isn't hot enough to re-ignite the wax vapour.