This is true, there's a different dynamic between two men and between a man and a woman. Maybe it's easier for 2 men to get along from the start.
Now about guys are not taught how to maintain a relationship, I wouldn't say that,, the really relates on what are the examples there are around you. A relationship requires attention and nurturing, as you said. I don't want to be sexist or degrading, but if a guy only had example of relationship where it's the woman that finally back down and always do the good thing for the couple, yes I can understand that that guy may have difficult to make things work in his relationships. But if you been living having example where the both make compromises and give into the relationship, well chances are that you'll know what to do to make things work. (hopefully this make some sense)
Of course it's more complicated that just that, but it can be a start
you guys already have a head start on most of everyone ; you guys are willing to make it last, and I'm sure that you guys are doing everything you can to make it last.
Kevin is totally right on this one,,, the only reason why you can see younger couple not lasting is that when you're young you're still changing,, you might still be student, and see thing differently,, then when you get to the working world, your mentality change and have different belief, different aspiration. It is easier to grow apart...