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!”
When I wanted to cut back on my drinking: “Just don’t buy it.”
Look, it’s great that you’ve never been addicted to anything, but it also means that you’re in no position to be offering addiction advice.