Having a fantasy based expectation. Not being realistic and not being ready to accept someone that may have some flaws. As do you yourself. If you can compromise on certain things and equally promise to work on issues in yourself. You'll be set on the right path.
There after, once you find a suitor... make sure that instead of going on dates. You go on "Marriage Meetups" Instead... these are upfront, no ghosts left behind in the cupboard style get together's to insure you know your potential spouse before you get married.
If you have a high matching percentage on our Marriage Material test... this is also a very good indicator that you two will have a very successful marriage and you love will be true and not a crush or something cheap.