Funny that "one-hit wonder" should have not one, but *two* (perhaps even three) "pot culture" meanings. Assuming the cannabis is of lower quality, it is foolish for somebody to begin acting crazy after one mere hit. On the other hand, exceptionally high-quality dank often requires only one good hit to satisfy its smoker. For this reason, some refer to high-quality pot as having "one-hit wonder" quality, because it only takes a hit to be fully satisfied. Another occasionally-used term is "one-hit shit," probably because it rhymes. The sad thing is, despite all of the great feelings one experiences immediately after taking a good toke, THC only begins to strongly affect the body and mind after about 5 minutes...so it's easy to go overboard, and smoke far more than you want to, which is a waste of weed, and a potentially negative experience to boot (depending on how much you like to be completely disoriented and aware of the blood pulsating in your carotid arteries). So next time you're smoking delicious nuggets of high quality pot, try waiting 5-10 minutes after your first hit and you can effectively gauge its quality. If you're not satisfied, keep on going. Pot that costs $300-400 per ounce should never take more than three hits before introducing the smoker to temporary nirvana. One or two is a much better deal.
Also, there is no true quantitative definition of a "hit." With the use of a decent water pipe, an experienced smoker can reduce a fully packed bowl to cinder in one breath. This experienced master can be appropriately labeled a "one hit wonder," although this isn't a very popular usage of the term, and the master won't be very popular at parties, unless it's their weed. The first mentioned usage (pertaining to quality), although somewhat corny, really is employed by people other than myself, most often marijuana seed banks attempting to hock their hopefully potent, hybridized strains.