Samba: This is meant as spirited debate, not as an attack, so please take it in that spirit. I find it a bit funny that you admit to smoking cigarettes and drinking alcohol, and then say drugs aren't for you. Guess what? You are already addicted to a recreational drug (nicotine), and you are an occasional user of another (alcohol). While the pros and cons are different for each recreational drug out there, there is no fundamental difference between them.
Memory loss: My memory is extremely bad. I often dont remember things from back when my wife and I were dating. It has nothing to do with drugs. I have a bad memory, and it was a long time ago. I've seen plenty of references to studies showing that pot causes temporary short term memory loss, but I've never seen any studies showing long-term or permanent memory loss from smoking pot. Not to say there are no such studies...I dont know for sure. I do know that aging causes long-term memory loss. We all age.