I've only experienced one-hit-quit weed twice in my life. Once, about 15 yrs ago...it was a strong greenhouse-grown NL5, and recently, just a few weeks ago...a super-strong OG Kush that a friend's friend grew hydroponically using AN's super-expensive "Connoisseur" line of nutes. So yes, one-hit-wonder weed does exist. It's a combination of good genetics AND excellent growing techniques.