When you're 45+ years old, you want a spouse who fulfills you intellectually, spiritually, and physically. This is the person whom you're going to be hanging out with most of the time. At this age, people don't go out as much with friends and so who you pick for a spouse is important. You want someone compatible and who will give you peace.
I don't need to know everything about my spouse, but we can only get to that point when a lot of trust has already been established. If he gives me anxiety then it just isn't going to work out. I might love him but he's not good for my health.