A successful life is determined by your decisions. There are only a few that really make a difference—who you associate with, who you marry, what you study, how hard you work at it, who you work for, how you manage your career, how you enjoy your family, and so on. Get these right and all will be well. Get one wrong, you can survive; get two wrong, you will not be happy, which is the only true definition of success.
In my experience every time I chose the harder path, it worked out. I studied chemistry undergrad, really hard, but I made it and that got me to Columbia. I nailed my MBA and that got me a great first job. I worked my tail off and I progressed through a good career. I married a like-minded but hard-to-get wife and had two great but challenging daughters. When in doubt, do hard things. There are fewer competitors and everything else seems easier. Jump high!