In late 2011 it seemed like a good business idea to build an iOS app. Got in way over my skis technically, went through some hard times, but came out unscatched and completely in love with coding.
Didn't know how to code, wrangled a hackathon, learned "managing offshore developers",
But it taught me to Lead from the Front, confirmed my interest in B2B, taught me the difference between a product and a business, and introduced me to some incredible friends and mentors.