<human>: I [22F] have been with my bf [26M] for just over a year. His parents divorced when he was 17 at which point he started smoking pot. Since then, he's messed around with various hallucinogens and psychedelics along with continuing to smoke. His use went on and off along with getting jobs, starting school, etc, but it never really stopped until we started dating. The last time he did anything was experimenting with X after we met, but shortly before we started dating. 

I am not okay with him doing any drugs at all. My worry isn't that he'll do drugs at some point while we're together (which would be an immediate deal breaker). My worry is that he stopped doing drugs because he's with me, and in the end, he's still the type of person who would be up for trying something new. Again, my worry isn't that he WILL do drugs, but that he'd be up for it if it weren't for me. 

At this point in our relationship, I'd like to start thinking realistically about what a future together would look like. This issue doesn't affect our relationship day to day, but when I think about things on a grander scale, this really bugs me.  It makes me really uneasy about our relationship and possibilities of a future as a whole. Am I being crazy about this, or am I allowed to be genuinely concerned? 

Last minute clarification: I did not know that he had ever had any involvement with drugs when we started dating. I actually thought he was a much different person than that. He told me about it all a few weeks into our relationship, and I expressed my opinions on drugs (I never forbade him from doing anything, but I did make it clear that doing drugs again was a deal breaker). At the time I didn't really have a problem with it for a few reasons. I was shocked and hadn't really processed what I'd heard, I thought he was a different person now, and he made it seem like it all happened a long long time ago. I found out a few months later that anything had happened recently, but it only happened rarely.

Condense the text into a few key points
<bot>: Bf used drugs for a significant period of his life, and stopped when he started dating me. Do people really change?