Patience, you see, is the crucial ingredient in any successful edible cannabis experience. The effects of eaten weed land between one and three hours after ingestion—a span that allows impatient partakers to hit the one-hour mark, decide they're "not feeling anything," and supplement their initial dose with another dose. Ugh
The result can be a cascade of intensifying effects, as the first dose eventually hits its mark, followed not long after by the supplementary dose—a double whammy that sends the user straight to the endless-seeming hell of the over-stoned lasting a day or more in some cases. It's dependent on the person and how strong and how much of the edible you ingested.