Ask HN: Whats your litmus test on whether to pursue a business idea

Even before putting up mock landing pages and buying traffic to see how it converts, how do you first filter your ideas and decide which one to pursue?

I have a business idea like every other week and I apply this quick 3 question test to see if I should spend more time research it or not.

1. Do I feel the pain of the problem myself?

2. Is this a universal problem?

3. Am I able to solve this problem?

Interested to see your versions of a litmus test. Would also be great to get feedback just in case I've missed an important question.

P.S I wrote more about my thinking at my blog pragmaticstartup.tumblr.com