This kind of a thing varies from person to person. I am the kind who'd need to think from before as to what I am gonna do next in order to get my work done properly..but I know lots of other people who are really spontaneous and can easily act on what they decide at that very mo. GG, imo, you should know what you want to. I mean there must be something you want to do, like for eg. the basic morale behind me choosing Medicals was cos I know helping others satisfies me. You should know what ultimately your aim is, how ultimately it is going to build you up and mix that idea with the subjects you'd need and are deeply interested in.