Li Wan, an ordinary middle school student, loves physics and "A Brief History of Time". He lives with his grandparents and occasionally meets and reunites with his father and new mother. Li Wan has a cousin who goes to the same school as him and has just fallen in love with a handsome and outstanding boy in the class, Gao Fang. In order to show his "unfaithful loyalty", Gao Fang got his cousin's name tattooed on on the arm.

Li Wan likes physics, but her father followed the teacher’s suggestion and asked her to change her interest class from physics to English. In order to make his daughter happy, one day, his father brought her a dog.

That dog was really small, always clinging to Li Wan, and it was timid and had to sleep on the same bed with Li Wan to stop barking. Li Wan found the dog really annoying, but slowly Let it depend on you, and even prepare pork liver rice for it, one for you and one for the dog. She named it Einstein.

But one day, Einstein went to the vegetable market with his grandfather and accidentally got lost.

Li Wan, who came back from school, knew this fact from the adults' evasive words, so he searched all over the world like crazy. On the streets, there was a skinny girl crying, "Einstein, woof woof." , where are you?" Even despite the adults' persuasion, the dog was lost and Li Wan's soul was also lost.

Finally, the impatient father got angry and used simple and crude "force" education to make his daughter "sober". At this time, the adults found a dog, which they said was Einstein. , but Li Wan knew that it was not. But who cares about a child's "unreasonable troubles".

Li Wan gradually became silent. She learned to drink from Gao Fang. On the back seat of Gao Fang's bicycle at night, she drunkenly asked Gao Fang, "What should a real adult be like?" Gao Fang said. "Don't take it too seriously, there will be many times like this in the future."

They will always think that you are a child, and things you promised can be forgotten in a blink of an eye, but they will remember the invitations of others;

They say it's wrong for you to drink, but they make you toast in front of your boss and friends just to "look good";

They don't care about your hobbies, they only care about your grades and whether you can be admitted to high school;

The world of adults has rules that children cannot understand. They do not understand children, and children do not understand them.

Li Wan first learned of his younger brother’s existence when he was two years old. His father pointed at the toddler on the skating rink, his eyes hesitant and said to Li Wan, “He... is Your brother."

At his brother's second birthday party, Li Wan broke away from his cousin's comforting hand and laughed.

But the dog still caused trouble. The new "Einstein" that Li Wan never cared about accidentally bit his younger brother. The dog's eyes once again begged his father, "Please don't send it to the restaurant to be killed," until his father's car drove away...

In the English speech contest, Li Wan expressed the universe in English, However, he stumbled and walked off the stage silently amidst the disappointed eyes of his father and the commotion in the audience. At home, his grandfather received the certificate of first place in the Li Wan Physics Provincial Competition.

Dad was very happy. He asked Li Wan, "What do you want? I will satisfy you."

Li Wan said, "I just want to know where Einstein was sent." "Restaurant."

Her father took her to the stray dog ??home. It turned out that he had not really sent the dog to be killed. Li Wan, who was now happy, found out at the shelter whether the dog had just been sent there. How long did it take for him to die on hunger strike?

On the way back in the car, his father hesitated to speak, but Li Wan smiled and said, "Thank you." Then he rejected his father's proposal to raise another one.

At his father's banquet, the so-called "uncle" gave Li Wan a piece of dog meat. Under the watchful eyes of everyone, Li joked, "Thank you, uncle" and ate the piece of dog meat.

In the car going home, during the singing of "Looking Back Again", his father covered Li Wan's eyes and started crying. He said, "I am not a good father, I am not..."

Li Wan accompanied his younger brother to learn skating. On the skating rink, an adult told him, "You have to stand up by yourself, stand up."

"So in the countless falls, the little boy who cried "I really can't do it..." stretched out his hands to the adults, always so lonely in the air, again and again...