So I was a heavy user. Every weekend, up to 5 pills a night, for years through college and into early 20s. This was back in the late 90s early 2000s. Now I am in my 40s. Top rated software engineer by my peers, sharp as hell, getting even sharper every year as my knowledge still grows, described as a true 10x expert engineer because of how much I do and code circles around everyone else. I am not saying this to brag. My point is simply that if there were some sort of permanant damaged cognitive effects, it never affected me like that. I never had any negative side effects ever. Or perhaps there was and I could have been the next Einstein but damaged myself to be where I am now. Guess I'll never know. I havent done again since I was around 22 or 23. It just stopped being enjoyable to me and everyone else I knew had already moved on past the party phase of their lives.

Also, a weird coindidence, during the heaviest usage phases, those were also my highest grades during college.

Do I regret using it so much? Not really. That was probably the happiest I've ever been in my entire life. I have very good memories , some of the best I've ever experienced. Often I think back I wish I could go back and do it again. Being an adult and getting old simply just sucks.