That's exactly right. In fact, these notions (I suspect) are the leading cause of relationship issues. We want to "fit" people into these imagined boxes. We measure our partners based on cultural expectations and our own dreams of an ideal mate. We turn these people that we "love" into objects for our own consumption. We are "buying" a life partner, making a socio-sexual "investment". But people aren't objects. And people don't fit into nice little imagined categories that you can pick out at Walmart. People are people, which means they are complex and will change over time. No one will fit into your box. No one will be your "100% perfect girl". Telling someone that they are your 100% perfect anything is a good way to psychologically abuse them. Especially if they are young and naive enough to believe you. To change themselves to try and fit into your box. Agreed again. We must first love ourselves. We must not seek someone else to complete us. If you love yourself, you will find someone that loves you for you, and you will find someone that complements and enhances your life. Maybe that will be for 1 year... maybe that will be for 100 years. There is no formula or equation that can tell you ahead of time what the outcome will be. You just have to live in the now and let life happen.There are certainly people we are more compatible with than others, but there's way too much emphasis placed on finding a soulmate or "the one".
I believe we should focus on selflessness and loving the one you're married to, not an eternal search for the mythical one that requires no effort other than finding.