Why do men usually call you back in a few seconds, and now they haven't called you back after three hours?

If you think a man will usually reply to your message within a few seconds, but now it has been three hours and six hours, and he hasn't replied to you. Then I think this is actually a very normal thing. After all, something might happen to him. I need to be busy, so I have no time to reply to your message. You just think too much about yourself. Everyone must have their own things to do. He usually replies to you in a few seconds, because he is waiting to reply to your message, but now he doesn't, because he is busy with something.