Probably even though you continued to smoke everyday you gradually smoked less and less and found that you could get just as high from less and less and continued to without noticing maybe. Same thing happend to me although on purpose so I could lower my tolerance, works well if any everyday smokers want to lower there tolerance. Also at least 6/7 days a week, only smoke in the evening. Since I started smoking grass at around 14 I found this is the best way to keep any small negative side effects, addiction and tolerance down. Also if you mix with tobacco, gradually add more tobacco and less grass ratio, very gradually.