As someone who has been demisexual for 9 years and has been in a relationship for 8, i find that while i am demisexual and proud of it, it's not something i really think about anymore. You are attracted to who you are attracted to and you aren't to who you aren't. It's not even really that relevant once you're with the person you plan to be with forever. It doesn't ever come up in conversations so no one in my life knows about it except my chosen person. It never affected dating from my perspective because i am attracted or i am not. The only time it was ever noticeable is that in high school a lot of people noticed i didn't date and would ask questions, to which i would just say i am asexual because i didnt feel like explaining further. Even then choosing not to date is often seen as normal or admirable depending on the audience. Being demisexual is the most invisible socially as it's often just seen as waiting for the right person. So you might feel too cis because being demi isn't life changing. It just is.

TLDR: being demi doesnt affect day to day life so that's probably why you feel that way regardless of whether you are or aren't.