your mind and body will thank you for it. this is coming from some one who is 20 years old and has been smoking on and off (never off for more than a month or two) for 6 or so years; its really nice to take a break sometimes. its not like its super addictive or anything, though it doesn't usually come without withdrawals in my experience. this is usually in the form of boredom, weed makes everything seem so interesting and more fun than it ordinarily would be! fortunately there aren't many physical changes that you would notice, just mental ones. as it stands right now i use it as a sleeping pill when i need to, for crippling back pain when necessary, and socially when i am feeling up to it, and not every day to boot, often just once a week. you're gonna do just fine, its not like the weed is going anywhere. and if you're nearing the end of highschool then you could not have picked a better time to do it. best of luck my friend, after graduation comes college if you're into that, and college can require weed for the stress haha.