李然(佟大为 饰)在偶然的际遇下和大学里的量子力学老师发生关系，而后这段没有结果的恋情给他留下了难以磨灭的影响。

　　几年后，已成为省报记者的李然在朋友的派对上邂逅了周蒙(江一燕 饰)，两人一见钟情，沉醉在爱情的浪漫美好中难以自拔。可是李然前女友刘漪的出现，不仅给两人带来短暂的纷争，更把杜晓彬(张歆艺 饰)带入了李然的生活。李然原本只是为了完成刘漪的心愿而去帮助杜晓斌，却渐渐被杜晓斌的倔强和才华所吸引。

　　尽管我们不断的用各种甜蜜片段情调爱情，可是青春究竟应该安放在何处，我们真的清楚么？

Li Ran (played by Tong Dawei) had a relationship with a quantum mechanics teacher in the university by chance, and then this fruitless relationship left an indelible impact on him. A few years later, Li Ran, who has become a reporter of the provincial newspaper, met Zhou Meng (played by Jiang Yiyan) at a friend's party, and the two fell in love at first sight and were intoxicated by the romantic beauty of love. However, the appearance of Li Ran's ex-girlfriend Liu Yi not only brought a short-term dispute between the two, but also brought Du Xiaobin (played by Zhang Xinyi) into Li Ran's life. Li Ran originally only went to help Du Xiaobin to fulfill Liu Yi's wish, but he was gradually attracted by Du Xiaobin's stubbornness and talent. Although we continue to flirt with various sweet fragments of love, do we really know where youth should be placed?