[zillionize]

Startup life is really hard - you will have to answer questions much harder than this every day if you do a startup. Therefore, based on my own first hand experience and observation on more than 100 startups I funded, only passion, determination and persistence can make your startup a success.

From this point of view, all the questions can come back to the root question - are you really passionate, determined and persistent by nature? If no working at Google or any other giant companies is way better than doing your own startup; Otherwise, you shouldn't come to Hacker News to ask this question but you have already quit Google because working at Google for one more day is just a waste of your time one more day.