I grew up around hills, not mountains, but when I first arrived in Michigan for college, the flat land was very odd to. Even flying into Detroit Metro seeing all the flat land from above was a little depressing. I still was aware of the flatness throughout my time there, but I had a lot of fun in school, so the flat land didn’t matter very much in the end.
Then I graduated and moved to South Florida where it is very flat also. The palm trees and sunshine make up for it. I’m still aware of it though. The sky is lower and broader when the land is flat. In the mountains it’s like the ceiling (sky and universe) above you is even higher.
Looking at beautiful things I think matters to a lot of people, and the mountains not only look beautiful, but I think it makes me feel cared for by nature, more in touch with the land, and has a tranquility.
However, I will say, after living in flat parts of the country for many years, I like the safety when driving down the road of being able to see all traffic, very few blind corners, very few turns that someone in the opposite lane can lose control and come into my lane because the are driving too fast on a curve, especially a down hill for them one. As I get older I appreciate it more.
When I drive through very mountainous states on the interstate especially, I find it exhausting. So much more attention needed.
Maybe part of what you miss is nature, did you live in a place that had houses farther apart, or more green space in general?