My father owned a successful mobile home dealership for about 40 years. As a teenager, and later in college, I did grunt work (mostly manual labor) at the business in the summers.

Later, in my mid-thirties, I left corporate software development for six or seven years, and managed the business for my dad. While I was there I wrote software to help me manage things, which, after I left the business to return to software development, I turned into the SaaS product which I've sold to other dealerships.