Getting old?

Last night I was laying on my couch, giving out advice through my new hobby....wizpert.com....which is in beta testing right now...trying to tell people how to work on their romantic or platonic relationships.....I know, who are you to give advice? Just a woman with a lot of life experience and the ability to listen and help people sort through their emotions. More on wizpert later though.
Anyways I got a text from The Cougar, whose nickname for this blog may need to change(-your about to find out why) regarding our favorite topic, men.
So let me catch you up on my favorite Cougar....She decided a few months back that she needed a relationship. Needless to say I was shocked. This is the one friend I have who had never previously even hinted at a desire for a relationship, quite the opposite exactly. I almost choked on my Pepsi that night in the middle of karaoke and all.
So, to continue on, we have a mutual friend, who is very much married and very much likes to cheat. She informed me he texted her, wanting to get a "drink". She had responded with perhaps. She then went on to inform that fwb's bore her now.
This lead me to contemplate why that is. There was a period of time that casual sex and fwb's were perfectly fine. However, I've noticed not only her, but many more of my friends are getting less about the casual and more about the commitment. The question is....Why? We aren't in mid-life crisis mode...yet. We financially support ourselves...It's it loneliness,? Is it maturity? Is it a fear of growing old alone? The jury is out on what motivates us to seek out stronger relationships with the opposite sex....hopefully it's got positive reasons not just to cure loneliness. I know from experience you can be just as lonely married as you are single. Perhaps we just like substance and quality over quantity.