some people (just) don't know when to stop

Said of someone who continues to engage in some action or activity after they have no hope of succeeding or are making things worse for themselves. A: "She keeps throwing money away on these failing investments. It's like she can't understand that they're never going to perform the way she wants." A: "Yeah, some people don't know when to stop." I told him to stop arguing with the boss like that, or he was going to get into even more trouble. Some people just don't know when to stop.