Not pulling out of that fertile broad? Car wreck that was your fault? Engagement/wedding ring?
Mine was earlier this year...made a mistake filling out my tax return, ended up getting about $3000 more than I should have. My car was having issues so I didn't question it and put it all into getting my shit fixed. The mistake was caught soon thereafter, now I gotta pay it all back in installments plus interest. Not all bad though, it basically amounted to a $3000 loan and the interest isn't bad since it was caught quickly. I should have it paid off by December.
What's your most expensive mistake?