Yes, this is very true. My experience is that as you get older you make fewer new contacts. It's not illogical, at first there is school, then university, then kids. All of these are excellent at making new friends but once the kids get old enough you stop naturally meet people outside of work, at least you have to put in some work for it to happen. I realized the other week that if I would not have my wife, it would easily be weeks between having a somewhat deep discussion with anyone outside of work. It's a terrifying thought.