The next big thing won't be forseen except by a select few, just like btc. But you can always keep an eye out for something interesting stop trying to find the next "big" thing and just look for what interests you and you will be on the right path don't think so much about money but think more about just enjoying your life and you will be ahead of the game (just my philosophy anyway)
This is true, unless you are on top of every single development in technology you will never find what is the next big thing before many people does it before you, but that is not really relevant, how many people found out about bitcoin before I did and yet I'm sure that I have obtained it reasonable profits compared to many people that came before me.