Have you ever gone some place and you have a choice of two things? How many have you gotten the right one the first time? I know my odds are never really 50/50.
Then there are the times I select something only to get home and find out it was the wrong one.
Or I get in one of the two lines and it is never the one that is the fastest. It is usually the one that there is something else is needed by the person in front of me.