Our startup, http://www.comprehend.com, makes software to help get new drugs on the market quicker and cheaper. One of the most appealing things about starting an enterprise startup are the size of the problems: the fine GSK is paying ($3bn) is almost as large as all AppStore revenue last year ($3.4bn). Another datapoint: Oracle's 2011 revenue was over $35bn.

If you're going to devote several years of your life to a startup, you owe it to yourself to make sure you are attacking a huge problem.