"If a bullfrog had wings it wouldn't bump his behind every time he hopped"

This quote by Don King is a humorous way of claiming that if something is not implied to be, it will not happen no matter just how hard you try. The bullfrog is a metaphor for a person who is trying to do something that is not suggested for them. The wings represent the ability to do something that is not natural for them. The suggestion is that if the bullfrog had wings, it would not have the ability to use them to jump, and also for that reason would certainly not bump its behind each time it tried. This quote is a tip that we must not try to do something that is not indicated for us, which we need to approve our constraints. It is likewise a reminder that we must not be also hard on ourselves when we fall short, as it is not constantly our fault.