You can say things like "back when I was single,..." or "when I was a bachelor,...". But what's the word for before you had a baby?
The best I can come up with is "back when I was free,..."
This blog will be a generous mix of rants and geeky information that I couldn't find a decent web reference for so I had to work it out myself. If you're not interested in something, I'd recommend you subscribe using the categories on the right.