It's funny how Jason Brody, a rich college kid with no survival skills, becomes a hardened killing machine over the course of a single night. Far Cry 3's story is obviously unrealistic in this sense, considering Jason would have probably been killed trying to escape Vaas' prison camp in a hypothetical real life situation, let alone manage to kill hundreds of pirates and mercenaries all by himself.
Let's assume you take the part as Jason and actually manage to escape the camp unscathed. What do you do and how long do you think you could go on?
I wouldn't even know where to begin searching for the friends. "But Dennis says your first friend is to the west"! I don't know how to read the stars, sorry.
Trying to escape by boat would be a bad idea considering you don't know exactly where you are or how far civilization is. Not to mention you could succumb to starvation, dehydration, or a storm over the ocean.
I know nothing of making pouches from animal hides nor do I know anything about mixing plants to create medicine. If anything, I'd probably end up poisoning myself.
I would probably suck at using guns since I've never used one in real life, and I sure as hell wouldn't be lugging around a freaking rocket launcher or light machine gun with me. I wouldn't be a good sniper considering you need to know how to compensate for bullet drop, wind, etc. in real life sniping. I'd probably miss most of the time with assault rifles and SMGs since I'll be crapping my pants when enemies shoot back at me. Archery takes years to master, so the bow is out of the question.
Therefore it leaves the last (and easiest) option: a self-inflicted .45 bullet to the head from a sixty dollar 1911 handgun. O_O The one shot I wouldn't miss.