But most people are not going to be 'very successful', and I am going to automatically assume that this is not included, since it's often statistically exclusionary (only a few people in the entire world can be olympic level sprinters).

It is most certainly not required to be 'great' to be socially successful, or, for that matter, interesting. As for my opinion of the whole 'greatness' chase, see here: http://lesswrong.com/lw/mmu/how_to_learn_a_new_area_x_that_you_have_no_idea/cu3o