First of all, let me start by saying I am an avid marijuana consumer. This post is not anti-weed. I am simply compiling the things I have learned about the plant in the many years I have used it.
Weed doesn't make you lazy. In fact, if you smoke the right strain it can make you fairly productive. Sativa strains tend to give you energy and stimulate creativity, while Indica strains tend to stimulate appetite (aka Munchies) and make you sleepy. Choose your strain based on what you want to achieve (if anything) while high.
Weed can help with depression. Consuming marijuana causes you brain to release dopamine which makes you feel that euphoria of being high. When consumed regularly (daily, every other day) it can help balance your serotonin levels. That's the chemical that keeps you mood level. Not only depression but, anxiety too. When consumed responsibly it can help general anxiety.
There are studies that show that weed can prevent and cure seizures, Alzheimers, cancer, et al. This is just one example of the many benefits.
The reason stoners got the lazy, deadbeat stereotype is all because of the Nixon administration. Weed was the drug of choice for the counter culture of the 70s so the government stepped in and used the stereotypes to wrest legitimacy from anti-Vietnam War activists. As St. Pierre says, "Regardless of your political affiliation, if you were a Vietnam War protestor, ergo, you were a pot smoking, non-working hippie." Then the War On Drugs started and millions of people (especially people of color) were sent to prison for struggling with an addiction or simply smoking a joint.
One drawback is that you can, in fact, get addicted to marijuana. Not in an addiction in the traditional sense but, you become emotionally and psychologically dependent on it. In order for this to become an issue you would have to be abusing the drug for years so don't worry yet.
Another thing they don't tell you is that in theory you could overdose on marijuana. While there are still ZERO reported deaths from THC, overdose it is possible. If you're smoking concentrated forms of THC like wax, hash, dabs, etc. then make sure you aren't overdoing it and greening out.
Sex while high is just OK. Everyone makes sex while high sound like bliss. It's fine. Don't have your expectations set too high because you'll just be let down. You're slow and your mouth is dry and your partner will probably be annoyed at your pace and lack of coordination.
Weed is like super illegal in Pennsylvania. I'm from Maryland and I go to school in New York so I have to drive through Pennsylvania to get home. I wasn't aware that possessing weed is a criminal offense there. They can arrest you then and there and you'll have to post bail. Don't dutch cruise in PA!
People CAN tell if you're high. No matter how good you think you are at faking sobriety someone WILL notice. Don't panic though, no one really cares about it anymore. You're unlikely to be reported or anything.
These are just a few of the things I wish I had known when I started smoking. I'm hoping these tips and facts help someone out there!