What's the most amount of money you've lost?

In this thread the question is asked about the most money you’ve ever found.

When I was first in Tokyo, I left my briefcase on the train with about 200,000 yen in cash in it (about $1500 at the time). I told the people at the station, and they contacted the station at the end of the line. Very fortunately, my bag was still on the train, so I got my money back, but it was quite the scare.

What’s the most money you’ve lost? Did you get it back?

My pay. I don’t know how much it was but it represented 100% of my net worth at the time. I had not a cent in the world afterwards.

$17 and my wallet. I was 11 years old. Very devastating.
Does it count if you know where it went? Lost $700 by losing 7 straight hands of Blackjack in a casino in Miss’ippi. Was doubling my bet each time to try to make up the loss. On the seventh hand, with over $300 on the table, I hit to 21. Dealer dealt himself blackjack and beat me, Blackjack-to-21.