Experiencing a different life with science fiction

Anna Persson on Mars in my novel
"Deserto rosso" (Red Desert)
Fiction books are entertainment, like cinema, music and so on. Yes, they are also supposed to be art, but this is not the point of this blog.
When we read, we immerse ourselves in another world. If the book is good enough, our selves get annihilated and by magic we are inside the story, experiencing what the characters are living, feeling their emotions. It’s like a journey in another life, without knowing where it will bring us, just like in real life, but with two big differences: we cannot control anything of what happens and we can withdraw from it at any time. But this does not make it less real and amazing.
Some books are so powerful that we spend the whole day waiting for the moment we can pick them up again and get back to the story. Some can make us laugh, or cry, be happy or sad. All of them have the power to make us experience a life which is different from our own.
Some books do even more than that, they can make us experience situations which nobody can actually experience in real life, not just us. This happens with speculative fiction, a macro genre which includes fantasy, horror, science fiction and other similar genres.
Being a science fiction writer, I’m particularly interested in what you can experience through this genre. Science fiction is also peculiar because it also treats some scientific themes, though in a speculative way, thus merging the magic of bringing readers to other worlds or times (or whatever) with giving them scientific information, sometimes very accurate one. When you read a sci-fi book, your fantasy is forced to work a lot to figure out the setting and action, but also to understand how things work, even if most of the science is not completely real.
As said in the previous post, a good sci-fi author is able to mix real science and fictional science so well that the reader can hardly see the difference.
The results of reading a sci-fi book can be very intense. You are brought to think about those fiction worlds even when you are not reading and, when you finish the book, you often find yourselves knowing something new. That’s why I love (good) science fiction.
But that’s also why I write this genre.
It’s very unlikely that I go to Mars in the future, okay, it’s impossible. But by writing a book set on Mars I am already there without travelling, without risking my life, without any stress. I can be whoever I want, do whatever I want, be wherever I want and feel it like it’s real.
A weird thing happens to me when I think back to a story I’ve written: I cannot recognized the difference between a memory of something I lived from the memory of something I had invented. Sometimes the memory of a story, since I have invented it in any detail, including the feelings of all the characters, seems to me more vivid than a real memory, which tends to fade away with time. Maybe it happens because my stories are definitely more exciting than my life (as said, I will never be able to go to Mars!), so my imagination is able to make me feel emotions which are stronger than most of those caused by real events.
Moreover you should not forget the power. In real life you can control only what you do (and not always), but once you’ve done something you cannot rewind and start again. Instead, while writing a book, you can control each element of the story and change it as many times as you like until you are perfectly satisfied. This control makes you feel powerful and, you know, it’s really fun.
And fun is really the reason why I write and also read.

Why do you read? Why do you write? What do you look for in a science fiction story, either as writer or reader?