My father had an army mate who emigrated to Canada straight after the war. In 1950 he returned and invited my dad to join him in his trucking business (they were both army drivers). He said he would stake my dad for 50% of the business, payable back over a few years, and they would be equal partners. My dad thought long and hard about it, but my mum was pregnant and I was barely two, so he declined.
His mate came back again in the early 70's, and looked my dad up. By that time he had a fleet of 70 trucks, four distribution warehouses and had just bought a small chain of supermarkets. He was as rich as Croesus and my dad had missed the opportunity of a life time. You win some, you lose some.