Character Analysis
Mark Watney is the man.
When we first meet him, he's your average, run-of-the-mill botanist. Nothing special. By the end of the novel, however, he's a dang hero. Although Mark didn't choose to be stranded on Mars, he made the best of the situation he was given, using his personality, intellect, and determination to fight his way out of an impossible bind.
Personality Test
The most important tool in Mark's arsenal is his winning personality. Think we're paraphrasing an inspirational poster? Think again.
Mark was chosen for the mission specifically because he was an asset to the group's chemistry—the way he "showed signs of stress and moodiness [...] was to crack more jokes and get everyone laughing" (8.136). For comparison: the way we show signs of stress and moodiness is to punch couch cushions, scream in the shower, and play very aggressive rounds of darts. None of that would be helpful on Mars.
But that's why they chose Mark to go to the red planet: when the going gets tough, tough Mark starts cracking jokes faster than an over-caffeinated Aziz Ansari:
Yes, of course duct tape works in a near-vacuum. Duct tape works anywhere. Duct tape is magic and should be worshipped. (17.50)
I tested the brackets by hitting them with rocks. This kind of sophistication is what we interplanetary scientist are known for. (18.107)
It's not that he doesn't grasp the seriousness of these situations, though. It's that he take away their power by making light of them. (In an interview, author Mark Weir is quoted as saying, "I guess people liked the snarkiness of the main character." We'd guess Weir is right on the money.)
And Mark Watney also just a supremely chill guy. For example, Mark doesn't even lose his cool when the crew leaves him behind. Instead of shouting their names angrily into the heavens, he writes that "in [their] position [he] would have done the same thing" and that he's "glad [they] survived" (1.13).
That's an awfully classy move coming from a guy stuck in a hopeless situation. But that's just how Mark works: no matter what gets thrown his way, he always manages to look to the bright side of things. That ability will be put to the test in a big, big way during his brief sojourn on the red planet.
Mark MacGyver
Mark's time on Mars consists of disaster after disaster. Things go from bad to worse—often.
Instead of admitting defeat, however, Mark puts a smile on his face and works harder at creating new solutions. And when those solutions fail—as they inevitably do—Mark keeps his nose to the grind. He even "prefers the term "learning experience" over the word "failure" (7.68). This borderline-improvisational approach to science gets him in trouble with NASA... but it's tough to argue with the guy's results. Or his pluck.
It helps that Mark has a lot of practice with this stuff by now. Over the course of his stay, Mark is forced to become the space-age version of MacGyver, staving of catastrophic disasters with some duct tape and a few strands of hair. Although "equipment failure is terrifying" to the bigwigs at NASA, "to [Mark], it's "Tuesday" (13.57).
This might sound cocky, but we think that Mark has earned the right to be a little cocky at this point.
There And Back Again
So how exactly do these experiences change Mark? To be honest, Mark remains fundamentally the same guy, even after he's rescued: he's still cracking jokes and being his lovably awkward self.
If anything, he walks away with a greater appreciation for life and the knowledge that "every human being has a basic instinct to help each other out" (26.424), which is a super-inspiring comment. Though he might be a bit more appreciative of each day, we seriously doubt that Mark Watney will transform into a different person when he gets back to Earth.
That being said—never say never. Although Mark is the same guy, he's returning to a very different world: a world where he is an uber-popular celebrity. Gone are the days of studying botany into the depths of night. Now he'll be rubbing elbows with politicians and movie stars and girls, girls, girls:
If I get back to Earth, I'll be famous, right? A fearless astronaut who beat all the odds, right? I bet women like that. (24.103)
Mark, you dog.
Naturally, there are downsides and upsides to this—just as there are with the worldwide obsession with Mark as a whole. Still, we can all agree that returning to Earth—and adapting to this new lifestyle—might be the guy's steepest challenge yet
Mark 2.0
To be honest, though, we're not too worried. No matter what gets thrown his way, Mark will assuredly face these new obstacles the same way he faced the ones on Mars—with a smile, a sense of humor, and a strong sense of intellectual curiosity.
That being said, all bets are off if Mark somehow scores a GQ photo-shoot: dude will be on the front page of TMZ in a matter of weeks.
Mark's Timeline