Blank dreams as in? If you mean having no dreams, that's completely natural.
Maybe you're waking up during deep sleep rather than REM, generally if we remember any of the nights dreams it's only the one we just woke up from. Maybe you are waking in REM and just forgetting anyway, that would make sense because dreams being on your mind after a conversation makes you more likely to remember. Next time you wake up with even a little bit of dream memory make a note of it, keeping a 夢日記 trains you to remember and sometimes when you just remember a little bit you get a lot more coming back by thinking about it. Forgetting dreams isn't like the normal kind of forgetting, it's an intrinsic response like a reflex, so starting to remember one gives you the rest for free.>>2677
Very few people actually don't dream, but a lot of people don't remember them and that's natural.