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!”
That would have been actually useful advice! I actually did start doing that a couple of years ago, and it really did help. It didn’t clear it up, but the acne hasn’t been quite as aggressive since. I also do other things now too, so I’m in a pretty good place for my face skin at last lol