I think a lot of people may see feeling content as feeling like they have settled. I know, personally, I feel like I have to have that amazing, butterflies-in-my-stomach all the time because that's what movies and TV tell us should happen. They don't show the Little Mermaid 3 years into the relationship when they argue and feel bored sometimes etc...

I think it's hard to distinguish content from settling but some people will always be looking for the next better thing. Sucks. But it's true.