The regret index

I just watched this video of Josh Petersen of 43 things talking about the process of filtering ideas to see which one is worth pursuing. This process is a critical one -- and one that is filled with contradiction and emotion.  in the video, he talks about using the notion of "regretting" not doing an idea as a way of sorting through ideas. I think he's totally right -- some ideas -- you just have to get out of your system...otherwise you'll regret not doing them.  That doesn't mean that the start up is going to be a raging success if you only use this method of sorting through ideas -- I just think it's one of the more important ways to sort through your ideas. So along side your spreadsheet of market size, capital needs, skill fit, add a column for the regret index when analyzing which of your ideas to pursue -- and which ones not to pursue.