Article below is a nice piece on why happiness = success:
http://hermannk.com/happiness-success/
I love the quote from Dave Greiner - " These days, my idea of success is a well-managed balance between time with people I love and a project I’m deeply passionate about. Right now, that’s Campaign Monitor. Time spent with each one of these has a huge impact on how much I enjoy the other. When I get that balance right, I’m at my happiest. And in the end, isn’t that what success is all about?"
For me, I'm going for a home run because I think it will allow me to have the biggest impact on the world. I was living in Chile for 6 months last year and have seen what my company (a p2p marketplace for trips planned by locals) could do globally. That worldwide impact is the driving force.
What it isn't is a money or peer pressure play. My first startup is actually set to double in revenue this year (to low-mid 6 figures) and I barely touch it. The money thing will come, whether I go for a home run or not.
I guess the important question to answer is: why are you going for a "home run"?
Is it because your life-consuming ambition, the only way you'll ever feel accomplished, is by having a bank account with a LOT of digits in it?
Is it because you have a burning ambition to change the world in a massive way via technology, like Steve Jobs or Mark Zuckerberg, and you just don't see any way to do it other than building a mega-company?
Or is it because you're letting your environment and peer pressure dictate that a home run is what you should want, even though what you really want is financial independence so you can spend more time reading books, travelling, and painting watercolours?