Drugs are divided into two categories: soft drugs and hard drugs.
This is generally common knowledge, but it cannot be stressed enough. It is important.
Soft drugs, such as alcohol and marijuana and caffeine: these can be taken into the body at any given moment and, provided that the taker is not overdoing it, they will provide comfort/euphoria/relief/entertainment, for up to a few hours. These are also naturally occurring substances, so for the human being to ingest them is plausible and understandable.
Hard drugs, such as PCP, heroin, cocaine, crack cocaine...these are all artificial, and for anybody to consume them is on par with walking into traffic without even looking left or right. You may reach the other side in one piece, or you may not, but don't forget that the trip out is always mirrored by the necessity of the return trip. What goes up must come down, and all that...
Marijuana: As close to communing with your ancestors as you can get. To smoke marijuana is to enter a state of relaxed and casual wonderment, for a time. Old things take on a new degree of interest, as they are re-examined seemingly "for the first time". The effect of marijuana is one of the inducing of a sense of novelty. Music becomes more detailed; you hear every individual part of the song, like never before.
Marijuana changes you in many ways, a fact which people try to skirt. I didn't used to like Snickers bars before I started smoking, but now I see them for their true nature: a bar of caramel and nougat and chocolate and nuts, fit for human consumption. God damn! I didn't like cheesecake, either, but now it is my favorite.
Marijuana has the effect of dispelling delusions and false ideas. You find yourself looking at how you and others interact with the world around, and go "Wow, that's stupid as shit" and then adapt to never behave that way again. This is a change. You hone yourself into a better you, but it also means that you may expect more from others. You will hit a wall when interacting with non-smokers, after enough years, because they literally don't get it. They can't be taught by words what you've learned through smoking c a n n a b i s.
Cannabis makes you creative. You will draw, or paint, or make sandcastles, or write music. You will post online in ways which you never had before. You will see through the facade of so much of human life, after you begin to smoke marijuana.
You will not regret smoking marijuana, in the same way in which you (generally) won't regret having a beer or two. Smoking marijuana is NOT like taking drugs, though.
Drinking coffee gets you wired.
Smoking cigarettes gets you buzzed.
Smoking weed gets you stoned.
Doing drugs gets you fucking high.
I've been high on numerous occasions and can say that it's more than anything a scary feeling at the time. You undoubtedly end up with an interesting story, but after slipping into an infinitely flat white void, I had to actually find my way back to our physical universe, before I could even attempt to find the Milky Way again. That sort of level of event doesn't happen with weed, except if you listen to a particularly enthralling piece of music, perhaps...
The 1000 years it took to get back left quite an impression on me.