To each his own, but I find the highlighted bit to be unreasonable and idealistic.
“Every” single moment of life…and “every” single issue will NOT be seen from a “different” perspective. There may be many times during the relationship where you and her will have similar opinions and views about various issues. I’ve even heard that (according to some research that I can’t remember) that extreme opposites have a harder time making the relationship work, rather a couple needs some common ground to bring them together.
And she doesn’t HAVE to be different in everything. What if you like vanilla…and she likes vanilla…but you both like vanilla for DIFFERENT reasons? You might like to eat vanilla plain…she might like to top vanilla with banana and hot fudge. It’s kind of like watching the same movie and having your own unique interpretation of it. Similarity can have “different” takes on it…and that too can be exciting.