Funny how little things remind you that you are growing up and are an actual adult. (besides marriages and babies and buying houses.)
It is getting increasingly harder to gather friends for even a casual get together. I sent out an email to friends yesterday to discuss a possible date for a Holiday / Winter party, and to figure out plans for a friends' bday in November, just to make sure we can all hang out! And, the winter party may have to move to January from it's original December setting due to schedule conflicts. No wonder connections w/ friends die down at a certain point in life. People get too busy with their own thing. It's tough though when people get offended by it. I have been the (unintentional) offender, and also found myself getting a bit annoyed at it at times.
I think it's one thing to just be busy and not be able to pick a date/time that works, but it's another to not even make the effort, or seem to not be into it. It's sad to see it happen to friends, when they give up on someone else because of lack of interest. I guess the whole 'he's just not that into you' goes for friendships too.