In order to enjoy a film like The Martian you will have to suspend disbelief since obviously what you get presented as real or fact is not real and just fiction. Of course a case could be made that some of the things you have seen might be scientifically accurate. But even then most of it is theoretical. Doesn't look like we will be sending people to Mars anytime soon.
But if you manage to go with what The Martian has to offer you will be in for a treat. It's full of suspense, thrills, action and last but not least comedy. Which to some seemed a little too optimistic and unreal. Only why would you think that? Of course most people would get scared and freak out but what good would that do? I think if anyone would be in the situation main character Mark Watney was in you would go in optimal survival mode and use your brain as efficient as possible. Remember it does take a special kind of person to become astronauts. They do have a certain mindset that make them act more fearlessly and practical. Also if you had been paying close attention Mark is affected by certain events only he tries to deal with them without his emotions getting in the way because that would only make things harder for him. His outlet is his humour. I did find his attitude inspiring. You never know when you yourself are going to be in a situation that forces you to survive. What are you going to if that happens? Would you just panic and cry your heart out and wait to die? Or would you just do whatever it is that you can do to live a day longer? I personally would take the latter. You should always try. If you tried and then failed you will have no regret. But if you don't try then it will infinitely worse. Although wondering what if would be the least of your problem since you would be dead. I think this film does show that people can do more than they realize. And they are capable of doing amazing things as long as you stay focused and motivated. Plus it would not hurt to keep yourself informed about science and what not. It might save your life one day.
I am surprised that I was fully into this film. Usually I don't like these films where the focus is on one person. Although that does depend on the narrative and genre. Fortunately The Martian covers a lot of angles and avoids the trappings of usually low budget solo survival films are victim of. Like staying in one location too long. Next to showing us multiple locations The Martian also makes good use of it's cast. Most of the characters have a real purpose. So when you see them it never feels like they are redundant. Whatever is being discussed or done by them matters to the plot. I found that very refreshing.
Although I do need to mention the following. Would NASA or whoever is in charge of all of this really waste all this time, money and energy into saving one man? Even when people get left behind on Earth some nations or institutions can't be bothered to take action because of the financial or political costs. Let alone they would go so far to rescue someone on Mars. I would like to believe that but it is very improbable. Still in the film they do say that this organization was being checked and monitored by the public and had a large say in these matters. I guess that would be an acceptable justification.
In the end it does not matter that much since you should not get too hung up on everything fantastic since this is science fiction after all. It's make believe and you just have to sit back and enjoy the ride. Certainly worth your time and a must watch.