[JohnBooty]

    But trying to make it out as everything being  
    possible and choices that you can just make 
    feels a bit like it can trivialize the difficulty 
    of actually doing it.

Well, you're certainly right: no relationship options are easy.

When I listed those options I was specifically referring to the parent poster, who equated middle age with automatically being in a stifling marriage.... as if marriage is just some inevitable thing that happens to you, rather than something you choose.

Which was certainly not to imply that the alternatives to marriage are easy. I mean yeah, relationships can be hard. And the lack of one can be hard too.