This book is sixteen lessons in which Cheng Wei-chuan (Seaweed Bear) and National Taiwan University's love research team distill more than a decade of their surveys and research analysis on how couples relate.

Its biggest difference from typical dating books: it doesn't teach you “how to be irresistible,” and offers no pickup tricks or charm secrets. Instead, it uses experimental data to show what ordinary people actually go through in relationships. Readers note that it steps outside binary gender frameworks and that its views are backed by the literature.

The book's premise is simple: people are different to begin with. Rather than copying someone else's formula for success, first get to know yourself, then act in a way that suits you, and you'll find someone who truly fits you.

The sixteen lessons follow the full arc of a relationship, in roughly three stages:

1. Love begins—the start of a relationship: Why do we want to be in love? Are we drawn to someone because we truly fit, or because of a passing illusion? What role do flirting and passion play?
2. Our love—sustaining the relationship: once the honeymoon phase gives way to the adjustment phase, how do two people communicate, face conflict and see each other's efforts?
3. The end of a relationship—another beginning: the final chapter looks at adjusting after a breakup, arguing that the end of one relationship can also be the start of something lovely.

Besides research findings, each lesson includes reflection questions so readers can compare it with their own experiences.

The book argues that to find a stable balance in a relationship, the first step isn't changing your partner but understanding what's happening inside you at each stage:

• When attracted: tell whether you're drawn to each other because you truly fit, or because of a passing illusion.
• When arguing: understand the inner conflict each of you is going through, and what you can do to make things better.
• When hurt: love makes you face your own inner wounds—many conflicts aren't really “incompatible personalities,” but old wounds being touched again in a new relationship.

The book uses the concept of attachment to explain that people react differently in intimate relationships. For example, people with anxious attachment need lots of reassurance and response, and feel uneasy when their partner seems even slightly cool.

Once you understand your own and your partner's attachment styles, it's easier to read each other's behavior: a partner not saying “I love you” doesn't mean they don't care, and your insecurity doesn't necessarily mean they did something wrong.

The book's most quoted idea: in a relationship, what matters isn't how much you give, but how much your partner sees, and how they respond.

• Love can be expressed in many ways: some say it, some show it. Learn to recognize your partner's way of expressing love, so you don't mistake “not saying it” for “not loving.”
• Tolerance is also love: the book notes that in Chinese culture, “tolerance” is often a way of expressing love.
• Don't mold your partner into your ideal: trying hard to reshape a partner into what you expect actually stops them from becoming who they really are.

The last lesson deals with adjusting after a breakup. The book's position is that the end of a relationship isn't only a loss but also a chance to know yourself again: look back at which old wounds the relationship touched and what patterns you fell into, so the next relationship doesn't repeat the same script.

The author later expanded this theme into another book, 暖傷心：失戀癒療的15個練習 (15 exercises for healing heartbreak), devoted to getting through a breakup.