[MPH LOW GRE + LOW GPA & ACCEPTED. I DID IT - SO CAN YOU: The tale of the underdog applicant]

It is perhaps feasible to get into a MPH program but does that same determination and persistence mean that you will also function well as an epidemiologist in a work environment?  I graduated from nursing school.  People weren't sure I could do it because of a head injury and physical limitations.  Yet I am not certain I can function well as a nurse given cognitive deficiencies that were previously unknown.  I don't want to go down another blind alley.  How far can determination and persistence really take you?