This quote from Dr. Seuss represents the very essence of hope and opportunity.  In a world where there is so much trepidation and fear about doing the wrong thing, Dr. Seuss' quote repudiates all of that.  It is indicating that if people take a step towards what lies ahead or what remains unknown, more can be gained than if they resisted doing so out of fear.  The idea of what can be found can only be achieved and understood if we overcome our fear and take a step forward.  The "things" that can be found will only be discovered if we "don't stay behind," suggesting that our own inhibitions, fears, prejudices, and negative thoughts with paralyzing doubt prevent our progress.  It is a statement that keys into the very idea of our own capacity for greatness should we only have the courage to embrace it.  The quote brings this out in full form and in a rhyme that seems to transcend time.  In the collection of lessons that Dr. Seuss teaches children and adults alike, this quote becomes one of the most dominant and proves to be the most true... 99 and 3/4 percent of the time!