I’ve had some privilege of being on the other side (longer terms in school/college). When we are out of touch with someone for few years, they become completely different and no longer the person you know. They may get married, have kids, or get divorced, or become filthy rich, or powerful, or disabled, or terminally ill or hundreds of different things. Some of my closest friendships were made in the last decade only, and are outside age or generation gaps. So as far as I’ve seen, you don’t really have to feel left out, because it doesn’t really seem to make a difference to most of the people :( Globalization, mobility, increasing competition, shortening time, attention-gathering gizmos, individual preferences and character, etc — they are all the new world norms. The ramifications of a postmodern society are not fully understood yet. A good example is typical westerner life. Maybe instead of having no kids — think about having two kids.