Reasons why people text others after midnight?

What are some reasons why someone would send a text or respond to a text after 2am? I have a friend who likes responding to texts after midnight even when he saw my texts way earlier. I don't mind delayed responses as long as its nothing important but I don't understand why he responds at midnight. If he was busy, why not just wait till the next day or something. It wakes people up and its kind of rude. Once I replied and told him to go to sleep but he still does it. Why do people think that's okay?
Reasons why people text others after midnight?
Post Opinion