THE CROSSROADS BETWEEN SHOULD AND MUST

I am really not sure about this crossroads concept.  I am a major planner, and I plan things years in advance so that I will not ever have to be caught off guard with a big decision.  My mind is generally mad up in advance.  I already know what my "must" is, and I follow it.  If I did not, I would not be at all be as driven with my work.  I tend not to do things that I do not consider musts, I just push them aside and out of my radar.  They have nothing to do with what I want to do.  This way, I truly only do what I want to do.  I study out of school because I want to.  I research because I want to.  I take AP courses because I want to.  Do you see me partying? No, because I do not want to.  I am lucky to like what society wants me to do, so most people's shoulds are my musts.