"You'll end up in a van down by the river" if you do drugs, don't go to college, etc. advice never includes the warning: "Don't suffer major Depression that gives you complete apathy for existence."
The post is saying that the helpful advice is about making choices and omits things outside of your control, like depression, that can lead to the same result.
It’s a sarcastic take on common advice. It’s implied by the inanity of the suggestion. Most people got it, wasn’t something you saw. You’ll get it next time :).