With a pretty lavish college student lifestyle you can live on $20K a year. If you're pulling down $100K+ (reasonable for an engineer or an IB, I imagine) that's at least 2 years of off time you buy with each year you work. Not that crazy, if you can control your spending :)

I made good money for my region, but it wasn't extrodinary given the hours I worked. By the end of the my two years I had enough to live (without any income) for at least 2 years as a single guy - so a good little nut. :-)

But I really didn't need that much to start my business - time to work was what was most important. I started my business (drop shipping eCommerce) with $1,500 and did sweat equity for the rest. I wanted to save that money to live on so I had maximum time to invest in bootstrapping.