If someone who has known you for a long time doesn't contact you for many years and suddenly sends you a message saying hi, how do you react?

Look at this person's position in your heart, or be clear about what you used to be. I think there are many things that can't be arbitrary. He may not be in when you want to chat. When you don't want to chat, maybe he will appear. If this person praises you through your circle of friends instead of chatting with you, it can only show that his relationship with you has not changed, but the feeling of chatting is not what it used to be. There is another kind of people, too many people. I put you in the address book, and I will say hello when I think of you. When I don't miss you, I will leave you. I hope I can help you and sit in the right position!