I went negative in net worth for a few years. I bought a condo in late 1994, at the age of 24, and started a slow burn after that. Then, I made the mistake of getting married in the summer of '95. She probably took me negative a few months after that. I'd say we bottomed out when we divorced in '96. I was close to $30K in credit card debt, and only had a few thousand $ saved up in mutual funds. So, I'd say I was about $27K negative, when we split. I did have some equity in the condo, but if I tried to sell it the commission/closing costs would take most of that. I also had several antique cars back then, but they wouldn't have been a quick sell, so I didn't count them as part of my net worth.
Oh, I almost forgot. I did have about $5,000 in savings bonds. I think I tend to forget those, because my Mom got them for me when I was a kid. So, even though they were "mine", they didn't really feel that way because I didn't "earn" them I guess. At one point, I did cash in a few hundred $, but kept the bulk of them intact. So, throw that in, and I guess I was "only" $22,000 in the hole.
Anyway, I took on a second job delivering pizzas, and soon after we split, I moved in with my grandmother and rented the condo out, to try and get that debt down quicker. In December of '97, even though I was still fairly deep in debt, I decided to start putting into my company's 401k plan. It wasn't much...initially I think just enough to get the company match, but it was a start. I do remember that by March of 1998, I was down to about $10,000 of credit card debt, and had it paid off in full by November of '98. So, I probably went to having a positive net worth sometime that summer.