I don't know how many people here have been in a modern dispensary or tried some of the high potency stuff they sell but it can be insanely strong. I got a 'super joint' one time as a gift, ultra high THC, laced with resin and covered in pure THC crystals. I made it about halfway through it before it actually gave me an anxiety attack, and I've had pot casually for a long time. My advice with weed is to go slow, it shouldn't take a lot for a decent effect. Chronic use affects you in ways you don't notice, basically being stoned all the time without feeling it.