Marrying my wife after letting her plan the wedding. It alone put us $30K in debt, We were already around $40K in debt...all from her excessive spending prior to us being together.

Talk about stupid...

But it turned better than I could have ever expected. We're mostly debt free now, and the only reason we have any debt is because I don't want to pay it off immediately since it's a 0% interest loan and the money is contributring to earning interest. So, I consider myself extremely fortunate for how it all turned out.