In short, knowing what makes you tick and what doesn't can help you empathize with people a little better .

When you realize what your partner does and doesn't care about, you can empathize better. Your reasons for fighting make a little more sense. When you understand why you're fighting, you're in a better position to come up with a solution.

Beyond fighting less (or at least more productively), the concept of love languages is a great for maintaining the relationship, too. For example, I know both of us feel affection by spending quality time together, so I know it's important to schedule this time to keeping our relationship strong. If we ever had a long distance relationship, we'd probably struggle quite a bit with it, and we'd need to put in more effort than people who don't speak the language of quality time. When you've been in a relationship for a long time, it's easy to get complacent and let things get stale. When you know your partner's love language, it's incredibly easy to recharge. It's like a cheat code for your relationship.