I started smoking weed when I was about 16 because my best friend suggested it and it sounded like fun. I tried it and it was pretty fun. I've smoked it pretty frequently for the past three years (one a week). The reason I continue is because almost all of my friends are the 'Stoner' type of people. Whenever we get together we smoke pot and listen to music and play video games and always have a good time.
I don't see any reason to stop smoking pot. Almost every medical study ever done has proven that regular weed smoking does not effect motivation or memory or your health. It is virtually impossible to overdose on pot, you need to consume nearly 40,000 times the amount of THC required to become intoxicated. So if 3 bong hits gets you stoned, 120,000 hits will be needed to kill you, which would cost hundreds of thousands of dollars and is impossible to smoke in a short enough time span. There have been zero reported weed overdoses in America. So weed is non-fatal and has no proven long term effects.
As far as the law is concerned. I live in Canada where weed is illegal but I have many friends who have been pulled over with at least 5 grams of weed on them and have only had it confiscated. Most arrests are at the officers discretion and as long as your polite and are not carrying enough to be a dealer, you should be fine. For the most part, when we smoke we do it at someone's home or in a private place, so even if someone calls the cops they would need a warrant to search the residence. When I smoke I never really worry about the cops but when I was younger and less comfortable with the drug I would often be paranoid of police.
People believe that marijuana leads to poor school performance or lack of motivation. I have been smoking weed since grade 10 and my grades have actually gone up from 65's to 80's in academic sciences and maths. Now I'm not naïve enough to believe that I do well because I smoke pot, I do well because of lots of hard work and studying, but pot has certainly not hurt my grades or my motivation.
Pot does not cause physical addiction, but anyone can get addicted to anything, especially if they have addictive personalities. It is not healthy to smoke weed in order to escape your problems but it can be a relief to people with a lot of stress in their lives. I know that when I have a lot of school work to over the weekend, it can be relaxing to smoke weed on the Friday to have a chance to relax and forget your problems. Some of my friends always smoke something called 'poppers', which is a mixture of weed and cigarettes smoked out of a bong, they are addicted to 'poppers' because of the chemicals in the cigarettes, not the weed. I never smoke anything other than strait pot. I also never smoked cigarettes because they are a proven health risk and I don't like the taste.
Finally, smoking weed is fucking fun. It makes everything you do more enjoyable, like video games, music, eating, or just talking with friends. Just observe a group of stoned people and listen to the crazy conversations and the hysterical laughter they produce. Laughing is good for your health and its a great way to bond with people. Unlike alcohol with makes you uncontrollable and sometimes violent, weed make you calm, and friendly; you also have complete control when your stoned and would not do anything you wouldn't do sober (except put peanut butter on Eggo waffles

). Also I would never try any other drug, because many of them do have harmful side effects. I don't care if someone smokes weed or not, but don't rag on it if you haven't tried it.
PS. to all you people who say you only tried weed once and didn't like it, you usually don't get stoned the first few times, so maybe try it more than once, you might come to like it.
TL;DR: weed is good.