Why doesn't the man I have a crush on return my messages? Is he busy at work or doesn't want to talk to me?

The first possibility is that he is very busy and has little time to reply to your message. The second possibility is that you send a text message to someone, and the other person has nothing to say or doesn't know what to reply to after receiving your text message. The third possibility is that people don't pay attention to it. Although they say they like you, they don't mean it. He doesn't really care about you. If he is kind to you, cares about you and is busy, that is the first possibility. If he is not good to you at ordinary times, or even has a close relationship, that is probably the third possibility. If he is usually kind and close to you, but introverted and has nothing to say to you, then it is probably the second. Well, that's my answer. If you think it is good, you can adopt it.