How long have you used cannabis? My memory was much better 20 years ago and I've never used cannabis.
On the other hand, there's a certain creative groove that's a lot harder to get into now. So there's a tradeoff.
I was experiencing lack of dreaming after some time of daily use, and was able to regain my ability to consistently dream (and remember them) by simply ceasing cannabis use by 5pm each day. I don't experience noticeable problems with memory, but YMMV.