Went to a seminar put on by a guy absolutely dominating his (non-Internet marketing) niche online.
Throughout the seminar he boasted about making so much money without a single backend or even upsell product (almost no one did upsell flows in those days).
I saw an opportunity so after seminar I contacted his office and said I have the perfect product for his customers, would he like to promote it as an affiliate.
His secretary relayed the message then got back to me to say "He'd love to see the product and marketing, send it over"
I had no product, no website and no idea!
So I hired writers and website developers and built an entire business in 3 weeks working 18 hours per day.
Sent everything for review with an apology for the delay due to technical difficulties (lol).
He loved it, agreed to promote and first ever email he sent I made over $1000.
It came the leading product in its category on Clickbank.
Meanwhile I became an Adwords expert and started driving 5000 clicks per day.
I was making A LOT of money and began living the lifestyle
Lesson: don't be afraid to fail big (that seminar guy was Frank Kern)