I'm 28 and my friends are just starting to get engaged/married. (We are a tribe of average bloomers.) I think one of the most interesting dynamics at play with weddings comes with the creation of the guest list: who makes the cut and who doesn't, who gets to decide who makes the cut, who gets plus-ones, and how people react to making the cut (or not.)
I have a friend from high school who recently got married and only invited three people from our high school group of friends. I was a little disappointed not to be included, but I chose not to be more hurt because as much as I like this woman, we're not as close as we used to be and only hang out a few times a year. She also has a large family and social circle from college, so it makes sense that she would not be able to invite everyone she was ever friends with. If she had invited me, she probably would have had to invite four or five other people from our group, most of whom have boyfriends , so that would add ten more people, which isn't cheap.
I still like the new bride as a person and I have made a point to continue to invite her and her husband to parties and events. They introduced me to my boyfriend of three years, so I owe them a lot. One of my other friends from high school did not take the lack of an invitation as well and keeps asking me why I include this couple in our lives when they consider us "B-list friends."
I don't have a good answer for her, other than the fact that I don't think the guests at your wedding represent the "A-list." There are family pressures and many other factors that go into deciding who's invited. My parents have been married for over thirty years and they barely talk to the people in their bridal party any more, let alone random wedding guests. Sure, weddings are important, but I don't think an invitation is a guarantee of lifelong friendship, so the lack of an invitation should not mean the end of a friendship either.
So, I'm curious to hear other people's thoughts on this. Have you ever been hurt by not being invited to a wedding? If you've been married, how did you decide who to invite and did you face any repercussions for your choices? People who have been married a long time, are you still close to the people who attended your wedding?