A pregnancy induced condition in which not enough white blood cells are manufactured. By the time our last one was born, she was producing none. She needed a transfusion while the birth was happening. She also has ongoing autoimmune conditions separate from that, and the medicine for them costs $50,000 a year.

My most successful investments were a couple of businesses I started (one with a 129x investment on $100k), Precious metals when they were far far cheaper than they are now (Silver was five dollars an ounce when I bought) and also domain names.

I lost money investing in a local gym, and a whole lot of money trying to compete with craigslist. Never put in more than I could afford to lose. Translation: I never lost so much that my wife complained.

I am theoretically at retirement age so I converted a bunch of cash into real estate without mortgages, I hold a fair amount of cash in case an opportunity arises, and I still invest aggressively in slightly risky tech index funds.