What does the quote things may come to those who wait but only things left by those who hustle?

It's saying that, although we all encounter good opportunities during the course of our lives simply by living day to do, those who go out and actively seek opportunities will get more chances at success. The ones who go out and hustle usually get the better deals and opportunities. Those who wait for opportunities to come to them by strokes of good luck usually don't get opportunities that are as good.