My point is simply calculating expected value. If you can't actually do that calculation, there are a lot of activities you should stay away from. The lottery,

My point is simply calculating expected value. If you can't actually do that calculation, there are a lot of activities you should stay away from. The lottery, poker, and startups all immediately come to mind. You may also want to reconsider getting in a car or crossing the street. Low probability of an event multiplied by a large outcome is not zero. It may be low (I do get in cars and cross the street) but people do regularly win the lottery, make money from stock, hit a straight on the river, and get hit by cars.