One rabbi compared wise men studying the law to children tossing a ball to one another: a first sage said the meaning was this, another said the meaning was that, one gave his opinion, another begged to differ.
The more energy you spend worrying about the people who didn't get on your bus, the less you will have for the people who are on your bus. And if you are worrying about the people who didn't get on your bus you won't have the energy to keep on asking new people to get on.