It's not too late to have your "party days". I am 28, I have 2 children, a mortgage and a full time job (as well as freelancing on the side). At the beginning of May I ended my 12 year relationship (manipulative, emotionally abusive ex) and jumped head first into a proper social life for the first time EVER. If I can do this whilst juggling being a lone parent / working 2 jobs / etc you have no excuses. :)
So go out to bars and have fun (who says you have to go with friends?!), date more, travel, take a class, swim in the ocean, jump from a plane, write a bucket list and do it all! Whatever, just make sure you seize life and get on with it.
Oh, but before you do all that, let me know how you manage to make enough to cover your bills in 8 hours so that I can jack in the full time job and spend more time with my kids ;)