I’ll go first: “You have to have children when you’re young,” told to me when I was in my late 20s, with no desire to ever have kids, and no means to support them, by someone divorced multiple times with at least one adult child who does not speak to them.
Also: Responding to “How do I deal with this problem?” questions with “Oh, don’t worry about it, it’s enough that you’re even thinking about it!”
Agreed, also people need to know how literal having “poor mental health” is. The margin you have for extra load or bad things happening is so much smaller. Similar to how an unexpected bill will be shoulder shrug for someone with good economy and a disaster for someone with bad economy.