Never Share salary/income??

So there this stigma about discussing salary or how much your income is and how you should not ask people things like how much they paid for thing...well I want to know. So if you dont wann share just dont. Question: Do you own your home.(2) how much was your home.(3) how much did you put down and where you get that money. How much is your mortgage. And just so I dont kicked would it be improper to ask friends and family those questions. Would you have you been asked.