Hey, I am also a junior so i know how it feels like to be in your situation. In fact I was in the same situation you were in during my sophomore year. Even though i was really peer pressured, Amazing as it might seem it was all the people who were saying ludicrous things against weed that convinced me to try it. i started to believe that there was no real argument against smoking weed and since all of the people who were saying bad things about it NEVER even took a hit in their whole lives I started to question why weed was opposed in general. In hope that you don't make the decision i will try as best i can to tell you my story.
but before i start i want to dispel some rumors first off Weed does NOT! kill brain cells and in most cases it does NOT lead to harder drugs. But what weed does do is alter your perception of the world around you. In adding chemicals to your brain you are changing your brain chemistry and by doing this you are ultimately "changing" your brain.
When i first started i was smoking weed once a week. at first it was great i was happy and started to see things in a new and unique way. however, after about 4 weeks of usage i started to note a change in my grades, my short term memory was shot, and my ability to handle stress was impaired. after only blazing up 8 or 9 times i decided to quit smoking weed, no big deal i thought the affects will ware off and i can continue with my life well i was in for a REALLY BIG surprise. after about a week of not smoking which was not too hard, since weed at first is very easy to quit, i was still feeling the same effects that i earlier described and IDK why but everything around me seemed slightly different. I went on line and was relieved to find that such a thing is normal after quitting and l thus i thought that it would pass. 3 weeks go by and i am convinced that something is wrong. I start to feel as if i was living in a dream. that nothing around me was real, i could't concentrate on problems and tasks like i used too. So far i was scared **** less because remember its been almost a whole MONTH since ive last smoked and i only blazed 9 times. My grades were dropping and i was convinced that i was going crazy. I did some research and discovered that what i had is called DE-REALIZATION disorder which is a stress related disease that can last a life time.. look it up.. another thing that i discovered is that smoking marijuana a daily basis for like 3 months increases your chances of developing schizophrenia by over 6 times(the average person has a 1% chances thus the average pot smoker has a 6% chance. anyways back to the story I always felt like i was kinda high no matter what i was doing and the feeling would never go away. it was scary as hell, and i almost had several panic attacks look that up too..Well i waited and waited for almost another month for the symptoms to go away and after much mental exercises and stress relief techniques i was able to return back to normality. You see what weed does is make u some calm that it slowly diminishes your ability to handle stress. Most pot smokers develop anxiety and short term problems that will stay with them their whole lives. After a couple months of feeling normal i decided to blaze up again..and of course the same problems returned. my point is that no matter what once you decided to take that giant step and smoke pot once it will always become a temptation that you will always have to deal with. Even after a couple of months of being clean i am still tempted to blaze up.
I hope that you have read this far and that my story has impacted you in some way. you seem like a smart kid why risk a possible mental or anxiety issue in the future just for a 4 hour high? That does not kill you, does not always always make you stronger