All I know is that I roll one joint a day, and take a few hits through the day. If it is a day to goof off and watch movies, I will smoke more, and that will make me feel a bit more of the effect, not feel like doing much except to watch the movie and snack, if I take a couple of hits, I may feel a buzz, but the stiffness in my joints (body joints) is abated and my movements are better. I will be 74 and have used pot for a very long time. Not everyone drinks more after one glass of wine, and they can do so without being considered under the influence, especially if it is with dinner. A glass of sherry at night is a lot different than 12 beers in a day. And you can pass out from too much pot, have you not heard the term "greening out", or eat more than one brownie? There is such a thing as couch lock. Moderation is the key.