I saw what he and his ex-girlfriend said before in my boyfriend's space. Although it has been a long time, why does it still hurt?

Because you care more about him, you love him more. Generally speaking, we only care about what happened before him, because we care about a person or love a person. Only when you love him will you be jealous of your ex-girlfriend or ex-boyfriend. This conversation between him and his ex-girlfriend proves that he may be happy during that time, and there was no you during that time. So when you read this passage now, it may really hurt a little.

Because you really still love him now, we all know that a person can be as strong as he wants. Why? Because he has no desire, naturally nothing can hurt him. Because you love him very much and care about him very much, you saw the evidence that he was in love with his ex-girlfriend before. That's why you are more heartbroken now. The starting point of all this is because you love him more. If not, it's just an ordinary passerby. We won't let our emotions fluctuate because of the experience of an ordinary person who has nothing to do with us, because that is a person we don't know. So because you care about him, in this case, you will care about his past and hope that you can create a better future with him.