"One morning I shot an elephant in my pajamas. How he got into my pajamas I'll never know"

This quote by Groucho Marx is an amusing way of expressing the concept that something can occur that is so unexpected and unusual that it is nearly difficult to explain. The expression "One early morning I shot an elephant in my pajamas" is a metaphor for an event that is so not likely and unusual that it is nearly impossible to understand. The phrase "How he got into my pajamas I'll never ever know" is a funny method of revealing the idea that the event is so strange and unforeseen that it is difficult to discuss. This quote is a funny method of revealing the concept that sometimes things occur that are so weird and unexpected that it is difficult to explain them.