Just make the new things to do, as big or small as you need.
I go to a lot of talks. I try to make sure they are about what i enjoy, but sometimes they have nothing to do with my interests. I meet new and
different people that way. I once went to a "Find your colour" talk, and ended up finding myself being the only guy in a room of about 200 women
talking about "what season are you when it comes to fashion?!
I was autumn apparently.
It was a laugh though, and i did learn some things for my own dress sense and my kids too.
Great suggestion about taking up an instrument.

Mine and my kids life has changed since learning guitar, our social circles have changed, music
tastes are much more varied, i go to places that are exciting and enjoyable rather than being sat round the bar of the local pub moaning about how
boring life is.
I'm only a beginner (been playing about a year), but if guitar ever tickles your fancy, i'll help online anyway i can. It's very easy when you are
shown by someone.
Do a search for "try a new thing every day", plenty of blogs and sites about that too.
Good luck, and thanks, whilst things are good here, it has reminded me that i can get stuck in the same habits so easily.
CX.
ETA: You could go overboard like mate of mine did....he volunteered to do a rally to Mongolia, you weren't allowed to use a car over 1200cc. He
bought an absolute heap! He experienced all sorts going over mountain ranges and across countries, some quite dodgy areas indeed. Best bit was.....he
needed a co-driver, so obviously you'd need someone you know well, with experience, a good navigator, all that yes?
Mongol Rally
He was walking through a town highstreet and saw a street performer playing guitar.....the conversation went like this.....and i mean as basic as
this!

....
Mate: Hi there, i'm doing a rally drive across 20 countries in a clapped out car.
Busker: Cool
Mate: I need a co-driver, do you fancy coming?
Busker: Yeah ok.
That was it!

edit on 5/10/12 by CX because: (no reason given)