Maybe a better way to say “people change” is “life changes you”. It’s unavoidable. If you don’t go into marriage realizing that her experiences will continue to shape her (potentially into someone you don’t like as much) as will your experiences shape you, you might be missing something. I love my wife now more than I did 20 years ago when we got married, but if you think we haven’t both changed, you’re fooling yourself. Many of the changes are for the better, but some are not. We are far more mature and more wise today than we were 20 years ago. We’re both passionate about things today we knew nothing about back then. Those are huge changes. We didn’t get there by simply knowing who the other person was from the start — though we did have that as you’re suggesting and it has its benefits. We got to here because love is an active pursuit that you never quit and you accept and embrace — even love — the changes that come along the way — even the changes that don’t seem lovable. Best Regards.