KNOW YOUR PLACE - PRACTICE SOME COURTESY

It will help you immensely in life if at every time you know your place and stick to it.
I send emails to my boss. She responds with jokes and emojis. One time to even communicate her agreement, she quoted lines from Big Shaq's song viral song. However in all my years of working with her, I have never been been tempted to reciprocate. My emails remain stiff and professional. I know my place. There is a line there and while she can cross it at will, I stay firmly on my side.

I go to someone's house today and I ask for a drink of water then they tell me to go get it from the fridge. The next time I come, I do not automatically assume that I can go into their fridge and take anything. I ask. I ask again and again.
I see two people bantering, making jokes and dissing each other. I do not suddenly think I can suddenly join in that banter. I am not part of their history, the history that enabled that banter. I know my place.
Someone gives me their phone number for a call. I do not automatically think to search for them on whatsapp and start messaging them instead. That wasn't the agreement.

You're friends with someone on Facebook. Do not go into the messenger and start calling them. They didn't give you that.
You're friends with someone on Facebook, by all that's sensible when you see them online (Messenger shows you're online once your data is switched on by the way) at night, do not go into the inbox to ask them "What are you doing awake?"
People have boundaries. Respect them. Know your place and don't just assume you can take privileges.

ASK FIRST... Practice some courtesy.