I have no close friends?

[Jesse]

This is not a self pitying post, more of an "is this normal?"

I am 27 and don't struggle to chat to people and make friendly acquaintance in social situations. I usually have people I really like at any given time point in my life - e.g at school then uni then at various workplaces. However, I never seem to strike up close enough friendships that last once these life phases end. For example, my best friends at university have moved on with their lives and tend not to feel the need to respond when I message as they're now both engaged and living with their partners. I can understand this - times move on.

When I'm not in a relationship, I have no one close and tend to have light hearted friendships that extend to occasional nights out in large groups. The older I'm getting, the more I'm worried that I may have social issue. My Facebook is litered with people who think I'm nice, but who I guess aren't really my friends outside of bigger groups. Is this normal, should I be worried?